Introduction
Looking for a delicious way to use your sourdough discard and fresh rhubarb? Moist Rhubarb Sourdough Discard Cake is a tender, tangy-sweet dessert that combines the tartness of rhubarb with a soft, lemony cake, all enhanced by the subtle tang of sourdough discard. Perfect for spring brunches, afternoon tea, or a cozy treat, this easy-to-make cake is both rustic and elegant, with a decorative rhubarb pattern on top. Ready to bake a cake that’s as flavorful as it is resourceful? Let’s get started!
Overview: Why This Rhubarb Sourdough Discard Cake Is Special
This Rhubarb Sourdough Discard Cake is a delightful way to repurpose sourdough discard, adding a slight tang that pairs beautifully with rhubarb’s tartness and the cake’s lemony brightness. The moist, tender crumb comes from a mix of oil, honey, and milk, while the rhubarb adds bursts of flavor and a stunning visual appeal. Easy to whip up with a stand or hand mixer, this cake is versatile (bake in an 8-inch or 9-inch pan) and stores well, making it ideal for make-ahead desserts. It’s a perfect balance of sweet, tart, and wholesome, great for bakers looking to reduce waste and celebrate seasonal produce.
- Time Requirement: 15 minutes prep, 33-40 minutes baking, 30 minutes cooling, ~1.25 hours total.
- Difficulty Level: Easy to moderate. Suitable for beginners with basic baking skills.
- Why It’s Special: This cake uses sourdough discard for unique flavor, showcases fresh rhubarb, and is moist, tender, and visually appealing. It’s perfect for spring and resourceful baking.
Whether you’re a sourdough enthusiast or a rhubarb lover, this Moist Rhubarb Sourdough Discard Cake is a must-try treat.
Essential Ingredients
This Rhubarb Sourdough Discard Cake uses pantry staples and fresh rhubarb for a flavorful, moist cake. Here’s what you need and why each one matters:
- Fresh Rhubarb (8 ounces, ~2 cups): Provides tart flavor and visual appeal; ¾ cut into ½-inch chunks for the batter, the rest into longer pieces for a decorative top pattern.
- All-Purpose Flour (170 grams, ~1⅓ cups): Forms the cake’s structure; lightly coats rhubarb to prevent sinking.
- Baking Powder (1½ teaspoons): Ensures a tender, risen crumb.
- Fine Salt (½ teaspoon): Balances sweetness and enhances flavors.
- Cane Sugar (155 grams, ~¾ cup, divided): Sweetens the cake (145 grams in batter, 10 grams for topping) and adds a slight crunch on top.
- Sunflower or Grapeseed Oil (½ cup): Keeps the cake moist and tender, with a neutral flavor.
- Lemon Zest (2 teaspoons): Adds bright, citrusy aroma to complement rhubarb.
- Eggs (2, room temperature): Bind the batter and add richness; room temperature ensures even mixing.
- Runny Honey (2½ tablespoons): Adds natural sweetness and moisture with a subtle floral note.
- Sourdough Discard (65 grams, ~¼ cup, preferably room temperature): Contributes slight tang and moisture, reducing waste.
- Vanilla Extract (1½ teaspoons): Enhances flavor with warm, sweet notes.
- Fresh Lemon Juice (1 tablespoon): Boosts tartness and balances sweetness.
- Whole Milk (2½ tablespoons): Adds moisture and tenderness to the crumb.
Substitutions and Variations
- Rhubarb: Use frozen rhubarb (thawed, drained, and patted dry); substitute ½ cup chopped strawberries or raspberries for part of the rhubarb (adjust sugar down by 1 tablespoon).
- Flour: Swap for gluten-free 1:1 baking flour for a gluten-free version; ensure proper weight (170 grams).
- Baking Powder: Ensure fresh for proper rise; no substitute without altering texture.
- Cane Sugar: Use granulated sugar or coconut sugar (may darken flavor); reduce topping sugar for less crunch.
- Oil: Replace with melted butter or avocado oil; butter adds richer flavor but may firm up when cold.
- Lemon Zest/Juice: Swap for orange zest/juice or omit zest (use ½ teaspoon more vanilla for flavor).
- Eggs: Use flax eggs (2 tablespoons ground flaxseed + 5 tablespoons water, let sit 5 minutes) for vegan, but texture may be denser.
- Honey: Substitute with maple syrup or agave nectar; honey adds unique flavor.
- Sourdough Discard: Use active sourdough starter (same amount) or increase flour by 30 grams and milk by 2 tablespoons if no discard (lose tangy flavor).
- Vanilla Extract: Omit or use ½ teaspoon almond extract for a twist.
- Milk: Swap for plant-based milk (e.g., almond, oat) for dairy-free; whole milk adds richness.
- Add-Ins: Mix in ¼ cup chopped walnuts or ½ teaspoon cinnamon to the batter for extra texture or warmth.
Pro Tip: Weigh ingredients (e.g., 170 grams flour, 65 grams discard) for accuracy, as volume can vary. Use room-temperature eggs and discard for a smoother batter; trim rhubarb’s woody ends for best texture.
Essential Equipment
- 8-inch or 9-inch Square Cake Pan: For baking; 8-inch yields a thicker cake, 9-inch a thinner one.
- Parchment Paper: For lining the pan to prevent sticking.
- Medium Bowls: For mixing rhubarb and dry ingredients.
- Stand Mixer or Hand Mixer: For beating the batter; a whisk and elbow grease work but take longer.
- Spatula: For folding rhubarb and smoothing batter.
- Cooling Rack: For even cooling post-baking.
- Toothpick: To test doneness.
Pro Tip: Grease and line the pan with parchment (leaving overhang) for easy removal; an 8-inch pan gives a taller, moister cake, while 9-inch bakes faster.
Step-by-Step Instructions
Making Moist Rhubarb Sourdough Discard Cake is straightforward with a mixer and a few simple steps. Follow this guide for a perfect cake:
- Prepare the Oven and Pan:
- Preheat oven to 350°F (177°C).
- Grease an 8-inch or 9-inch square cake pan and line with parchment paper, leaving overhang for easy removal.
- Tip: Ensure parchment covers the bottom and sides; grease lightly under and over parchment for extra insurance.
- Prep the Rhubarb:
- Trim and cut 8 ounces rhubarb: ¾ (6 ounces, ~1½ cups) into ½-inch chunks, the rest into longer pieces (2-3 inches) to fit diagonally across the pan for decoration.
- Place chunks in a medium bowl.
- Tip: Cut rhubarb uniformly for even baking; save prettiest pieces for the top pattern.
- Mix Dry Ingredients:
- In another medium bowl, whisk 170 grams all-purpose flour, 1½ teaspoons baking powder, and ½ teaspoon fine salt.
- Scoop 2 heaping teaspoons of this mixture into the bowl with the rhubarb chunks and toss to coat (prevents sinking in batter). Set both bowls aside.
- Tip: Toss rhubarb gently; a light flour coating is enough.
- Make the Batter:
- In a stand mixer (or large bowl with a hand mixer), beat 145 grams cane sugar, ½ cup sunflower or grapeseed oil, and 2 teaspoons lemon zest on medium speed for 1 minute until slightly frothy and sugar begins to dissolve.
- Add 2 room-temperature eggs and beat on medium for 30 seconds until frothy and well combined.
- Add 2½ tablespoons runny honey, 65 grams sourdough discard, 1½ teaspoons vanilla extract, 1 tablespoon fresh lemon juice, and 2½ tablespoons whole milk. Mix on medium speed until just combined, about 15 seconds.
- On low speed, gradually add the dry flour mixture, mixing just until no flour streaks remain (do not overmix).
- Tip: Scrape the bowl as needed; stop mixing once flour is incorporated to keep the cake tender.
- Fold in Rhubarb:
- Gently fold the flour-coated rhubarb chunks into the batter using a spatula. It’s okay if some flour is visible on the rhubarb.
- Tip: Fold carefully to avoid crushing rhubarb; ensure even distribution.
- Assemble the Cake:
- Pour the batter into the prepared pan and smooth the top with a spatula.
- Arrange the longer rhubarb pieces on top in a decorative pattern (e.g., diagonal lines or a lattice).
- Sprinkle the top evenly with the remaining 10 grams (2 heaping teaspoons) cane sugar for a crunchy finish.
- Tip: Press rhubarb pieces lightly into the batter; sugar adds sparkle and texture.
- Bake the Cake:
- For an 8-inch pan: Bake at 350°F for 25 minutes, then reduce oven to 330°F (166°C) and bake 15 minutes more, until a toothpick inserted in the center comes out with a few moist (not wet) crumbs.
- For a 9-inch pan: Bake at 350°F for 20 minutes, then reduce to 330°F and bake 8-10 minutes more, until a toothpick tests similarly.
- Tip: Check doneness early to avoid overbaking; tent with foil if the top browns too quickly.
- Cool and Serve:
- Remove the cake from the oven and cool in the pan on a cooling rack for 30 minutes.
- Lift the cake out using the parchment overhang, slice, and serve warm or at room temperature (makes 9-12 servings).
- Store in a sealed container in the refrigerator for up to 4 days.
- Tip: Let cool slightly for cleaner slices; serve with whipped cream or yogurt for extra indulgence.
Cooking Tips:
- Prevent Overbaking: Check with a toothpick early; moist crumbs indicate doneness, while a wet batter needs more time.
- Rhubarb Placement: Arrange top rhubarb pieces thoughtfully for a pretty presentation; avoid overlapping too much.
- Mix Gently: Overmixing the batter can make the cake dense; fold rhubarb with care to maintain tenderness.
Assembly: Serving Your Rhubarb Sourdough Discard Cake
Serving Moist Rhubarb Sourdough Discard Cake is all about highlighting its tender crumb and tart rhubarb:
- Serve Warm or Room Temperature:
- Serve 1 square (1/9 or 1/12 of the pan) per person as a dessert or snack, perfect with coffee or tea.
- Tip: Warm slices briefly (microwave 10 seconds) to revive moisture; room temperature enhances flavors.
- Presentation Tips:
- Dust with powdered sugar or drizzle with a lemon glaze (½ cup powdered sugar + 1 tablespoon lemon juice) for elegance.
- Garnish with fresh rhubarb slivers or a lemon zest sprinkle for a pop of color.
- Serve on a platter to show off the rhubarb pattern on top.
- Serving Ideas:
- Pair with whipped cream, vanilla ice cream, or Greek yogurt for a creamy contrast.
- Serve with fresh berries or a dollop of rhubarb sauce for a rhubarb-forward dessert.
- Offer at brunches, picnics, or potlucks alongside muffins, scones, or fruit tarts.
- Portioning:
- Makes 9 large or 12 smaller servings from an 8-inch or 9-inch pan.
- Cut into smaller pieces (16-20) for bite-sized treats at gatherings.
Pro Tip: Serve with a scoop of vanilla ice cream and a drizzle of honey for a decadent, restaurant-worthy dessert.
Storage and Make-Ahead Tips
This Rhubarb Sourdough Discard Cake stores well and can be prepped ahead:
- Storage:
- Room Temperature: Store in an airtight container for up to 1 day; best fresh.
- Fridge: Store in a sealed container in the refrigerator for up to 4 days; rhubarb keeps the cake moist.
- Freezer: Freeze sliced or whole cake (wrapped tightly in plastic wrap and foil) for up to 2 months. Thaw in the fridge overnight before serving.
- Reheating:
- Microwave: Warm individual slices for 10-15 seconds to restore softness.
- Oven: Reheat at 300°F for 8-10 minutes, wrapped in foil to prevent drying.
- Tip: Refresh with a sprinkle of sugar or a glaze after reheating for a fresh-baked feel.
- Make-Ahead:
- Prep rhubarb and dry ingredients up to 1 day ahead; store rhubarb in the fridge and dry mix covered at room temperature.
- Make the batter (without rhubarb) up to 4 hours ahead, refrigerate, and fold in rhubarb just before baking.
- Bake the cake up to 2 days ahead, store in the fridge, and serve at room temperature or warmed.
- Tip: Add decorative rhubarb and topping sugar just before baking for the best appearance.
Pro Tip: Freeze individual slices for quick snacks; wrap each in parchment for easy thawing and reheating.
Recipe Variations
Make Moist Rhubarb Sourdough Discard Cake your own with these fun twists:
- Strawberry Rhubarb Cake: Replace ½ cup rhubarb chunks with chopped strawberries; reduce sugar by 1 tablespoon for balance.
- Spiced Rhubarb Cake: Add ½ teaspoon cinnamon or ¼ teaspoon cardamom to the dry ingredients for warmth.
- Nutty Rhubarb Cake: Fold in ¼ cup chopped walnuts or pecans with the rhubarb for crunch.
- Gluten-Free Rhubarb Cake: Swap all-purpose flour for a 1:1 gluten-free baking flour (170 grams); ensure sourdough discard is gluten-free.
- Vegan Rhubarb Cake: Use flax eggs (2 tablespoons ground flaxseed + 5 tablespoons water, let sit 5 minutes), plant-based milk, and maple syrup instead of honey; replace oil with melted vegan butter.
Healthier Twist:
- Reduce sugar to 120 grams (~½ cup) in the batter for a less sweet cake; keep topping sugar for texture.
- Use whole wheat pastry flour (170 grams) for added fiber; mix with 1 tablespoon extra milk if batter is thick.
- Replace half the oil with unsweetened applesauce (¼ cup) for lower fat; cake may be slightly denser.
- Serve with Greek yogurt instead of ice cream for a protein-rich topping.
Conclusion
Moist Rhubarb Sourdough Discard Cake is a tender, flavorful dessert that celebrates the tartness of rhubarb and the tangy depth of sourdough discard. Perfect for spring gatherings or cozy evenings, this easy-to-make cake is both resourceful and delicious, with a stunning rhubarb pattern that impresses every time. Customize with spices or berries, and enjoy it warm with a scoop of ice cream or a dollop of whipped cream. Grab your sourdough discard and let’s bake a cake that’s as moist as it is memorable! What’s your favorite way to use rhubarb in desserts?
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Moist Rhubarb Sourdough Discard Cake
Description
Looking for a delicious way to use your sourdough discard and fresh rhubarb? Moist Rhubarb Sourdough Discard Cake is a tender, tangy-sweet dessert that combines the tartness of rhubarb with a soft, lemony cake, all enhanced by the subtle tang of sourdough discard.
Ingredients
This Rhubarb Sourdough Discard Cake uses pantry staples and fresh rhubarb for a flavorful, moist cake. Here’s what you need and why each one matters:
- Fresh Rhubarb (8 ounces, ~2 cups): Provides tart flavor and visual appeal; ¾ cut into ½-inch chunks for the batter, the rest into longer pieces for a decorative top pattern.
- All-Purpose Flour (170 grams, ~1⅓ cups): Forms the cake’s structure; lightly coats rhubarb to prevent sinking.
- Baking Powder (1½ teaspoons): Ensures a tender, risen crumb.
- Fine Salt (½ teaspoon): Balances sweetness and enhances flavors.
- Cane Sugar (155 grams, ~¾ cup, divided): Sweetens the cake (145 grams in batter, 10 grams for topping) and adds a slight crunch on top.
- Sunflower or Grapeseed Oil (½ cup): Keeps the cake moist and tender, with a neutral flavor.
- Lemon Zest (2 teaspoons): Adds bright, citrusy aroma to complement rhubarb.
- Eggs (2, room temperature): Bind the batter and add richness; room temperature ensures even mixing.
- Runny Honey (2½ tablespoons): Adds natural sweetness and moisture with a subtle floral note.
- Sourdough Discard (65 grams, ~¼ cup, preferably room temperature): Contributes slight tang and moisture, reducing waste.
- Vanilla Extract (1½ teaspoons): Enhances flavor with warm, sweet notes.
- Fresh Lemon Juice (1 tablespoon): Boosts tartness and balances sweetness.
- Whole Milk (2½ tablespoons): Adds moisture and tenderness to the crumb.
Substitutions and Variations
- Rhubarb: Use frozen rhubarb (thawed, drained, and patted dry); substitute ½ cup chopped strawberries or raspberries for part of the rhubarb (adjust sugar down by 1 tablespoon).
- Flour: Swap for gluten-free 1:1 baking flour for a gluten-free version; ensure proper weight (170 grams).
- Baking Powder: Ensure fresh for proper rise; no substitute without altering texture.
- Cane Sugar: Use granulated sugar or coconut sugar (may darken flavor); reduce topping sugar for less crunch.
- Oil: Replace with melted butter or avocado oil; butter adds richer flavor but may firm up when cold.
- Lemon Zest/Juice: Swap for orange zest/juice or omit zest (use ½ teaspoon more vanilla for flavor).
- Eggs: Use flax eggs (2 tablespoons ground flaxseed + 5 tablespoons water, let sit 5 minutes) for vegan, but texture may be denser.
- Honey: Substitute with maple syrup or agave nectar; honey adds unique flavor.
- Sourdough Discard: Use active sourdough starter (same amount) or increase flour by 30 grams and milk by 2 tablespoons if no discard (lose tangy flavor).
- Vanilla Extract: Omit or use ½ teaspoon almond extract for a twist.
- Milk: Swap for plant-based milk (e.g., almond, oat) for dairy-free; whole milk adds richness.
- Add-Ins: Mix in ¼ cup chopped walnuts or ½ teaspoon cinnamon to the batter for extra texture or warmth.
Pro Tip: Weigh ingredients (e.g., 170 grams flour, 65 grams discard) for accuracy, as volume can vary. Use room-temperature eggs and discard for a smoother batter; trim rhubarb’s woody ends for best texture.
Instructions
- Prepare the Oven and Pan:
- Preheat oven to 350°F (177°C).
- Grease an 8-inch or 9-inch square cake pan and line with parchment paper, leaving overhang for easy removal.
- Tip: Ensure parchment covers the bottom and sides; grease lightly under and over parchment for extra insurance.
- Prep the Rhubarb:
- Trim and cut 8 ounces rhubarb: ¾ (6 ounces, ~1½ cups) into ½-inch chunks, the rest into longer pieces (2-3 inches) to fit diagonally across the pan for decoration.
- Place chunks in a medium bowl.
- Tip: Cut rhubarb uniformly for even baking; save prettiest pieces for the top pattern.
- Mix Dry Ingredients:
- In another medium bowl, whisk 170 grams all-purpose flour, 1½ teaspoons baking powder, and ½ teaspoon fine salt.
- Scoop 2 heaping teaspoons of this mixture into the bowl with the rhubarb chunks and toss to coat (prevents sinking in batter). Set both bowls aside.
- Tip: Toss rhubarb gently; a light flour coating is enough.
- Make the Batter:
- In a stand mixer (or large bowl with a hand mixer), beat 145 grams cane sugar, ½ cup sunflower or grapeseed oil, and 2 teaspoons lemon zest on medium speed for 1 minute until slightly frothy and sugar begins to dissolve.
- Add 2 room-temperature eggs and beat on medium for 30 seconds until frothy and well combined.
- Add 2½ tablespoons runny honey, 65 grams sourdough discard, 1½ teaspoons vanilla extract, 1 tablespoon fresh lemon juice, and 2½ tablespoons whole milk. Mix on medium speed until just combined, about 15 seconds.
- On low speed, gradually add the dry flour mixture, mixing just until no flour streaks remain (do not overmix).
- Tip: Scrape the bowl as needed; stop mixing once flour is incorporated to keep the cake tender.
- Fold in Rhubarb:
- Gently fold the flour-coated rhubarb chunks into the batter using a spatula. It’s okay if some flour is visible on the rhubarb.
- Tip: Fold carefully to avoid crushing rhubarb; ensure even distribution.
- Assemble the Cake:
- Pour the batter into the prepared pan and smooth the top with a spatula.
- Arrange the longer rhubarb pieces on top in a decorative pattern (e.g., diagonal lines or a lattice).
- Sprinkle the top evenly with the remaining 10 grams (2 heaping teaspoons) cane sugar for a crunchy finish.
- Tip: Press rhubarb pieces lightly into the batter; sugar adds sparkle and texture.
- Bake the Cake:
- For an 8-inch pan: Bake at 350°F for 25 minutes, then reduce oven to 330°F (166°C) and bake 15 minutes more, until a toothpick inserted in the center comes out with a few moist (not wet) crumbs.
- For a 9-inch pan: Bake at 350°F for 20 minutes, then reduce to 330°F and bake 8-10 minutes more, until a toothpick tests similarly.
- Tip: Check doneness early to avoid overbaking; tent with foil if the top browns too quickly.
- Cool and Serve:
- Remove the cake from the oven and cool in the pan on a cooling rack for 30 minutes.
- Lift the cake out using the parchment overhang, slice, and serve warm or at room temperature (makes 9-12 servings).
- Store in a sealed container in the refrigerator for up to 4 days.
- Tip: Let cool slightly for cleaner slices; serve with whipped cream or yogurt for extra indulgence.
Cooking Tips:
- Prevent Overbaking: Check with a toothpick early; moist crumbs indicate doneness, while a wet batter needs more time.
- Rhubarb Placement: Arrange top rhubarb pieces thoughtfully for a pretty presentation; avoid overlapping too much.
- Mix Gently: Overmixing the batter can make the cake dense; fold rhubarb with care to maintain tenderness.
FAQs
Q: Can I use frozen rhubarb?
A: Yes, thaw, drain, and pat dry frozen rhubarb to remove excess liquid. Use as directed; baking time may increase by 2-3 minutes.
Q: What if I don’t have sourdough discard?
A: Increase flour by 30 grams (~¼ cup) and milk by 2 tablespoons to compensate. The cake will lose the tangy flavor but remain moist.
Q: Why did my rhubarb sink?
A: Skipping the flour coating or using wet rhubarb can cause sinking. Toss rhubarb with the flour mixture and pat dry if frozen.
Q: Can I make this gluten-free?
A: Yes, use a 1:1 gluten-free baking flour (170 grams) and ensure sourdough discard is gluten-free (from a gluten-free starter).
Q: Why is my cake dry?
A: Overbaking or overmixing can cause dryness. Check doneness early with a toothpick and mix batter just until combined.
Q: Can I use a round pan instead of square?
A: Yes, an 8-inch or 9-inch round pan works; baking times are similar to the square pan (check with a toothpick).
Q: Can I double the recipe?
A: Yes, double ingredients and use a 9×13-inch pan. Bake at 350°F for 30 minutes, then 330°F for 15-20 minutes, checking doneness.
Q: Is this cake vegan-friendly?
A: Not as written, but use flax eggs, plant-based milk, and maple syrup instead of honey for a vegan version; texture may vary slightly.