Introduction
Craving a sweet-tart, gluten-free dessert that’s perfect for spring or summer? Gluten-Free Raspberry Rhubarb Crumble Bars combine a buttery oat crust with a vibrant raspberry-rhubarb compote, topped with a crunchy crumble. These bars are naturally gluten-free, using oats and oat flour, and feature a jammy filling that’s both tangy and sweet. Ideal for picnics, potlucks, or a cozy afternoon treat, they’re easy to make and even better after chilling for a firm, sturdy texture. Ready to bake these delicious bars? Let’s get started!
Overview: Why These Gluten-Free Raspberry Rhubarb Crumble Bars Are Special
These Gluten-Free Raspberry Rhubarb Crumble Bars are a delightful balance of textures and flavors, with a crisp oat crust, a juicy compote filling, and a crumbly topping. The raspberry-rhubarb compote adds a bright, tart-sweet layer, while the gluten-free oats and brown sugar create a comforting, buttery base. Easy to prepare with pantry staples, these bars are perfect for gluten-free diets and shine at gatherings or as a make-ahead dessert. Chilling after baking ensures clean slices and enhances their flavor, making them a versatile, crowd-pleasing treat.
- Time Requirement: 20 minutes prep, 25-30 minutes cooking compote, 37-42 minutes baking, 2 hours chilling, ~3.5-4 hours total.
- Difficulty Level: Easy to moderate. Suitable for beginners with basic baking skills.
- Why It’s Special: These bars are gluten-free, feature a vibrant raspberry-rhubarb filling, and have a perfect balance of textures. They’re easy, portable, and taste best chilled for a firm texture.
Whether you’re gluten-free or just love the classic rhubarb-raspberry pairing, these Crumble Bars are a delicious, seasonal delight.
Essential Ingredients
These Gluten-Free Raspberry Rhubarb Crumble Bars use wholesome ingredients for a flavorful, gluten-free treat. Here’s what you need and why each one matters:
Compote
- Rhubarb (2 cups, 225 grams, diced, fresh or frozen): Provides tartness and a juicy texture; pairs perfectly with raspberries.
- Organic Raspberries (1¼ cups, 170 grams, fresh or frozen): Adds sweet-tart flavor and vibrant color.
- Raw Cane Sugar (⅓ cup + 1 tablespoon): Sweetens the tart fruits and helps thicken the compote.
- Zest and Juice of One Lemon (~1 teaspoon zest, 2-3 tablespoons juice): Enhances tartness and brightens flavors.
- Cornstarch or Tapioca Starch (3 teaspoons): Thickens the compote for a jammy consistency.
- Vanilla Extract (½ teaspoon): Adds warmth and depth to the filling.
Base and Crumble
- Gluten-Free Old Fashioned Oats (¾ cup, 80 grams): Provides chewy texture and hearty flavor; use certified gluten-free.
- Oat Flour (1 cup, 100 grams): Adds structure and a nutty, gluten-free base.
- Lightly Packed Brown Sugar (½ cup): Brings caramel-like sweetness and helps crisp the crust.
- Tapioca Starch (1 tablespoon, or cornstarch): Enhances crispiness and binds the base.
- Baking Powder (1¼ teaspoons): Ensures a light, tender crust.
- Sea Salt (¼ teaspoon): Balances sweetness and enhances flavors.
- Cinnamon (¼ teaspoon): Adds subtle warmth to the crumble.
- Melted Organic Vegetable Shortening (½ cup, e.g., Nutiva coconut/palm oil spread, or butter): Binds the crust and crumble, adding richness; shortening keeps it dairy-free.
Substitutions and Variations
- Rhubarb: Swap for additional raspberries or strawberries (maintain 225 grams); adjust sugar down by 1 tablespoon if sweeter fruit is used.
- Raspberries: Use blackberries or mixed berries; frozen works well (no need to thaw).
- Raw Cane Sugar: Replace with granulated sugar or coconut sugar; coconut sugar darkens flavor slightly.
- Lemon Zest/Juice: Use orange zest/juice or 1 teaspoon apple cider vinegar for tartness.
- Cornstarch/Tapioca Starch: Swap interchangeably (same amount); arrowroot powder works too.
- Vanilla Extract: Omit or use ¼ teaspoon almond extract for a twist.
- Oats/Oat Flour: Ensure certified gluten-free; replace oat flour with almond flour (100 grams) for a nuttier base, but adjust shortening to ⅓ cup.
- Brown Sugar: Use coconut sugar or granulated sugar; reduce to ⅓ cup for less sweetness.
- Shortening/Butter: Swap for melted coconut oil, vegan butter, or regular butter (not dairy-free); coconut oil may solidify when chilled.
- Cinnamon: Replace with nutmeg, cardamom, or omit for a plainer crumble.
- Add-Ins: Mix ¼ cup chopped nuts (e.g., almonds, pecans) or 2 tablespoons shredded coconut into the crumble for extra crunch.
Pro Tip: Weigh ingredients (e.g., 80 grams oats, 225 grams rhubarb) for precision, as gluten-free baking benefits from accuracy. Use certified gluten-free oats to avoid cross-contamination; dice rhubarb finely for even cooking in the compote.
Essential Equipment
- Heavy-Bottomed Saucepan: For cooking the compote evenly without burning.
- 8×8-Inch Baking Pan: For baking the bars; square shape ensures even layers.
- Parchment Paper: For lining the pan to prevent sticking and easy removal.
- Large Mixing Bowl: For combining base and crumble ingredients.
- Whisk: To blend dry ingredients smoothly.
- Spatula or Spoon: For pressing crust and mixing.
- Fork: For pricking the crust before baking.
- Cooling Rack: For cooling bars to maintain texture.
Pro Tip: Cut parchment to overhang the pan for easy lifting; lightly grease the pan before lining to secure parchment.
Step-by-Step Instructions
Making Gluten-Free Raspberry Rhubarb Crumble Bars is straightforward with these clear steps. Follow along for perfect bars:
- Make the Compote:
- In a heavy-bottomed saucepan, combine 2 cups (225 grams) diced rhubarb, 1¼ cups (170 grams) raspberries, ⅓ cup + 1 tablespoon raw cane sugar, zest and juice of one lemon.
- Bring to a hard boil over medium heat, stirring to dissolve sugar, then reduce to a simmer for 10 minutes.
- Add 3 teaspoons cornstarch or tapioca starch, stir to dissolve, and cook for 3 minutes more until slightly thickened.
- Stir in ½ teaspoon vanilla extract, remove from heat, and cool for 15 minutes.
- Tip: Stir frequently to prevent sticking; compote should be jammy but not overly thick (it sets more when baked).
- Prepare the Oven and Base:
- Preheat oven to 350°F (177°C).
- In a large mixing bowl, whisk 1 cup (100 grams) oat flour, ¾ cup (80 grams) gluten-free old fashioned oats, ½ cup lightly packed brown sugar, 1 tablespoon tapioca starch, 1¼ teaspoons baking powder, ¼ teaspoon sea salt, and ¼ teaspoon cinnamon.
- Stir in ½ cup melted organic vegetable shortening (or butter) until no white streaks remain and the mixture is crumbly.
- Tip: Mix thoroughly to ensure even distribution; use a fork to break up clumps for a uniform crumble.
- Form the Crust:
- Line an 8×8-inch baking pan with parchment paper, leaving overhang for easy removal.
- Press a heaping cup of the oat mixture firmly into the pan using the back of a spatula or spoon to create a smooth, even crust.
- Prick the crust with a fork 5-6 times to prevent puffing.
- Tip: Press firmly for a sturdy base; a spoon helps smooth edges and corners.
- Bake the Crust:
- Bake the crust at 350°F for 12 minutes, until fragrant and lightly browned.
- Remove from oven and let cool for 10 minutes.
- Tip: Check at 10 minutes to avoid over-browning; cooling helps the crust set before adding compote.
- Assemble and Bake:
- Spread 1¼ cups of the cooled rhubarb-raspberry compote evenly over the crust.
- Sprinkle the remaining oat mixture over the compote to form a crumble topping.
- Bake for 25-30 minutes, until the topping is golden brown and the compote is bubbling slightly.
- Tip: Spread compote gently to avoid disturbing the crust; crumble topping loosely for texture.
- Cool and Chill:
- Remove from oven and let cool on a cooling rack for 1 hour.
- Refrigerate for at least 1 hour (or overnight) to firm up for clean slicing.
- Lift bars out using parchment overhang, cut into 9-16 squares, and serve chilled or at room temperature.
- Tip: Chilling is key for sturdy bars; use a sharp knife for clean cuts.
Cooking Tips:
- Compote Consistency: Cook until thickened but still spreadable; it firms up during baking and chilling.
- Prevent Soggy Crust: Cool the crust and compote before assembling; prick crust to release steam.
- Even Baking: Rotate the pan halfway through the final bake for uniform browning; tent with foil if topping browns too quickly.
Assembly: Serving Your Gluten-Free Raspberry Rhubarb Crumble Bars
Serving Gluten-Free Raspberry Rhubarb Crumble Bars is all about highlighting their tart-sweet filling and crumbly texture:
- Serve Chilled or Room Temperature:
- Serve 1 square (1/9 or 1/16 of the pan) per person as a dessert, snack, or breakfast treat, perfect with coffee or tea.
- Tip: Chilled bars are firm and sturdy; room temperature enhances compote flavor but may be softer.
- Presentation Tips:
- Arrange on a platter to show off the vibrant compote and crumble topping.
- Dust with powdered sugar or drizzle with a lemon glaze (¼ cup powdered sugar + 1 teaspoon lemon juice) for elegance.
- Serve in parchment liners or on small plates for a bakery-style look.
- Serving Ideas:
- Pair with vanilla ice cream, whipped cream, or yogurt for a decadent dessert.
- Serve with fresh raspberries or a mint sprig for a pop of color.
- Offer at picnics, brunches, or potlucks alongside cookies, brownies, or fruit salads.
- Portioning:
- Makes 9 large or 16 smaller squares from an 8×8-inch pan.
- Cut into smaller pieces (25 bite-sized) for party trays or buffets.
Pro Tip: Serve chilled with a scoop of vanilla ice cream and a drizzle of reserved compote for a restaurant-worthy dessert.
Storage and Make-Ahead Tips
These Gluten-Free Raspberry Rhubarb Crumble Bars store well and can be prepped ahead:
- Storage:
- Room Temperature: Store in an airtight container for up to 1 day; best fresh.
- Fridge: Store in an airtight container or wrapped in the pan in the refrigerator for up to 5 days; chilling enhances texture.
- Freezer: Freeze cut bars (wrapped individually in plastic wrap and placed in a freezer bag) for up to 2 months. Thaw in the fridge overnight or at room temperature for 1 hour.
- Reheating:
- No reheating needed; serve chilled or at room temperature.
- For a warm treat, microwave individual bars for 10-15 seconds (crumble may soften).
- Tip: Refresh with a sprinkle of oats or powdered sugar after thawing for a fresh look.
- Make-Ahead:
- Prepare compote up to 3 days ahead; store in an airtight container in the fridge (use within 1 week).
- Mix dry ingredients for base/crumble up to 1 day ahead; store in an airtight container at room temperature.
- Bake bars up to 2 days ahead, refrigerate, and cut before serving.
- Tip: Save extra compote (if any) for topping yogurt or ice cream; freeze in small portions for later use.
Pro Tip: Freeze bars in single layers separated by parchment to prevent sticking; ideal for grabbing one at a time.
Recipe Variations
Make Gluten-Free Raspberry Rhubarb Crumble Bars your own with these twists:
- Strawberry Rhubarb Bars: Replace raspberries with strawberries (170 grams); reduce sugar in compote to ⅓ cup.
- Blueberry Rhubarb Bars: Swap raspberries for blueberries; add ½ teaspoon lemon zest to the crumble for brightness.
- Spiced Crumble Bars: Add ¼ teaspoon nutmeg or ginger to the crumble for extra warmth.
- Nutty Crumble Bars: Mix ¼ cup chopped almonds, pecans, or walnuts into the crumble topping for crunch.
- Vegan Crumble Bars: Use vegan butter or coconut oil instead of shortening; ensure sugar is vegan (some cane sugars use bone char).
Healthier Twist:
- Reduce brown sugar to ⅓ cup and cane sugar to ¼ cup for a less sweet bar; increase lemon zest for flavor.
- Use unsweetened applesauce (2 tablespoons) to replace 2 tablespoons shortening for lower fat; texture may be softer.
- Add 2 tablespoons ground flaxseed to the crumble for extra fiber and omega-3s.
- Serve with Greek yogurt instead of ice cream for a protein-rich topping.
Conclusion
Gluten-Free Raspberry Rhubarb Crumble Bars are a delightful, gluten-free dessert that’s perfect for showcasing the tart-sweet magic of rhubarb and raspberries. With a buttery oat crust, jammy compote, and crunchy crumble, these bars are easy to make, versatile, and even better after chilling for clean slices. Ideal for picnics, brunches, or cozy treats, they’re a wholesome way to enjoy seasonal flavors. Grab your rhubarb and raspberries and let’s bake a batch of bars that’s sure to impress! What’s your favorite fruit combo for crumble bars?
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Gluten-Free Raspberry Rhubarb Crumble Bars
Description
Craving a sweet-tart, gluten-free dessert that’s perfect for spring or summer? Gluten-Free Raspberry Rhubarb Crumble Bars combine a buttery oat crust with a vibrant raspberry-rhubarb compote, topped with a crunchy crumble.
Ingredients
Compote
- Rhubarb (2 cups, 225 grams, diced, fresh or frozen): Provides tartness and a juicy texture; pairs perfectly with raspberries.
- Organic Raspberries (1¼ cups, 170 grams, fresh or frozen): Adds sweet-tart flavor and vibrant color.
- Raw Cane Sugar (⅓ cup + 1 tablespoon): Sweetens the tart fruits and helps thicken the compote.
- Zest and Juice of One Lemon (~1 teaspoon zest, 2-3 tablespoons juice): Enhances tartness and brightens flavors.
- Cornstarch or Tapioca Starch (3 teaspoons): Thickens the compote for a jammy consistency.
- Vanilla Extract (½ teaspoon): Adds warmth and depth to the filling.
Base and Crumble
- Gluten-Free Old Fashioned Oats (¾ cup, 80 grams): Provides chewy texture and hearty flavor; use certified gluten-free.
- Oat Flour (1 cup, 100 grams): Adds structure and a nutty, gluten-free base.
- Lightly Packed Brown Sugar (½ cup): Brings caramel-like sweetness and helps crisp the crust.
- Tapioca Starch (1 tablespoon, or cornstarch): Enhances crispiness and binds the base.
- Baking Powder (1¼ teaspoons): Ensures a light, tender crust.
- Sea Salt (¼ teaspoon): Balances sweetness and enhances flavors.
- Cinnamon (¼ teaspoon): Adds subtle warmth to the crumble.
- Melted Organic Vegetable Shortening (½ cup, e.g., Nutiva coconut/palm oil spread, or butter): Binds the crust and crumble, adding richness; shortening keeps it dairy-free.
Substitutions and Variations
- Rhubarb: Swap for additional raspberries or strawberries (maintain 225 grams); adjust sugar down by 1 tablespoon if sweeter fruit is used.
- Raspberries: Use blackberries or mixed berries; frozen works well (no need to thaw).
- Raw Cane Sugar: Replace with granulated sugar or coconut sugar; coconut sugar darkens flavor slightly.
- Lemon Zest/Juice: Use orange zest/juice or 1 teaspoon apple cider vinegar for tartness.
- Cornstarch/Tapioca Starch: Swap interchangeably (same amount); arrowroot powder works too.
- Vanilla Extract: Omit or use ¼ teaspoon almond extract for a twist.
- Oats/Oat Flour: Ensure certified gluten-free; replace oat flour with almond flour (100 grams) for a nuttier base, but adjust shortening to ⅓ cup.
- Brown Sugar: Use coconut sugar or granulated sugar; reduce to ⅓ cup for less sweetness.
- Shortening/Butter: Swap for melted coconut oil, vegan butter, or regular butter (not dairy-free); coconut oil may solidify when chilled.
- Cinnamon: Replace with nutmeg, cardamom, or omit for a plainer crumble.
- Add-Ins: Mix ¼ cup chopped nuts (e.g., almonds, pecans) or 2 tablespoons shredded coconut into the crumble for extra crunch.
Pro Tip: Weigh ingredients (e.g., 80 grams oats, 225 grams rhubarb) for precision, as gluten-free baking benefits from accuracy. Use certified gluten-free oats to avoid cross-contamination; dice rhubarb finely for even cooking in the compote.
Essential Equipment
- Heavy-Bottomed Saucepan: For cooking the compote evenly without burning.
- 8×8-Inch Baking Pan: For baking the bars; square shape ensures even layers.
- Parchment Paper: For lining the pan to prevent sticking and easy removal.
- Large Mixing Bowl: For combining base and crumble ingredients.
- Whisk: To blend dry ingredients smoothly.
- Spatula or Spoon: For pressing crust and mixing.
- Fork: For pricking the crust before baking.
- Cooling Rack: For cooling bars to maintain texture.
Pro Tip: Cut parchment to overhang the pan for easy lifting; lightly grease the pan before lining to secure parchment.
Instructions
- Make the Compote:
- In a heavy-bottomed saucepan, combine 2 cups (225 grams) diced rhubarb, 1¼ cups (170 grams) raspberries, ⅓ cup + 1 tablespoon raw cane sugar, zest and juice of one lemon.
- Bring to a hard boil over medium heat, stirring to dissolve sugar, then reduce to a simmer for 10 minutes.
- Add 3 teaspoons cornstarch or tapioca starch, stir to dissolve, and cook for 3 minutes more until slightly thickened.
- Stir in ½ teaspoon vanilla extract, remove from heat, and cool for 15 minutes.
- Tip: Stir frequently to prevent sticking; compote should be jammy but not overly thick (it sets more when baked).
- Prepare the Oven and Base:
- Preheat oven to 350°F (177°C).
- In a large mixing bowl, whisk 1 cup (100 grams) oat flour, ¾ cup (80 grams) gluten-free old fashioned oats, ½ cup lightly packed brown sugar, 1 tablespoon tapioca starch, 1¼ teaspoons baking powder, ¼ teaspoon sea salt, and ¼ teaspoon cinnamon.
- Stir in ½ cup melted organic vegetable shortening (or butter) until no white streaks remain and the mixture is crumbly.
- Tip: Mix thoroughly to ensure even distribution; use a fork to break up clumps for a uniform crumble.
- Form the Crust:
- Line an 8×8-inch baking pan with parchment paper, leaving overhang for easy removal.
- Press a heaping cup of the oat mixture firmly into the pan using the back of a spatula or spoon to create a smooth, even crust.
- Prick the crust with a fork 5-6 times to prevent puffing.
- Tip: Press firmly for a sturdy base; a spoon helps smooth edges and corners.
- Bake the Crust:
- Bake the crust at 350°F for 12 minutes, until fragrant and lightly browned.
- Remove from oven and let cool for 10 minutes.
- Tip: Check at 10 minutes to avoid over-browning; cooling helps the crust set before adding compote.
- Assemble and Bake:
- Spread 1¼ cups of the cooled rhubarb-raspberry compote evenly over the crust.
- Sprinkle the remaining oat mixture over the compote to form a crumble topping.
- Bake for 25-30 minutes, until the topping is golden brown and the compote is bubbling slightly.
- Tip: Spread compote gently to avoid disturbing the crust; crumble topping loosely for texture.
- Cool and Chill:
- Remove from oven and let cool on a cooling rack for 1 hour.
- Refrigerate for at least 1 hour (or overnight) to firm up for clean slicing.
- Lift bars out using parchment overhang, cut into 9-16 squares, and serve chilled or at room temperature.
- Tip: Chilling is key for sturdy bars; use a sharp knife for clean cuts.
Cooking Tips:
- Compote Consistency: Cook until thickened but still spreadable; it firms up during baking and chilling.
- Prevent Soggy Crust: Cool the crust and compote before assembling; prick crust to release steam.
- Even Baking: Rotate the pan halfway through the final bake for uniform browning; tent with foil if topping browns too quickly.
FAQs
Q: Can I use only rhubarb or raspberries for the compote?
A: Yes, use 395 grams (3¼ cups) of either rhubarb or raspberries. For rhubarb-only, increase sugar to ½ cup; for raspberry-only, reduce to ¼ cup.
Q: Is this recipe truly gluten-free?
A: Yes, if using certified gluten-free oats and oat flour. Check labels for cross-contamination, especially with oats.
Q: Why is my crust soggy?
A: Hot compote, an underbaked crust, or excess fruit liquid can cause sogginess. Cool compote and crust before assembling; drain frozen fruit well.
Q: Can I make these vegan?
A: Yes, use vegan butter or coconut oil instead of shortening; ensure cane sugar is vegan (some use bone char). Texture remains similar.
Q: Why did my bars fall apart?
A: Insufficient chilling or too much compote can cause crumbling. Chill for at least 1 hour and use exactly 1¼ cups compote.
Q: Can I use a different pan size?
A: Yes, a 9×9-inch pan makes thinner bars (reduce final bake to 20-25 minutes); a 7×7-inch makes thicker bars (increase to 30-35 minutes).
Q: Can I double the recipe?
A: Yes, double all ingredients and use a 9×13-inch pan. Increase final bake time to 30-35 minutes; compote cooking time remains the same.
Q: Can I skip chilling the bars?
A: Chilling is recommended for firm, clean slices, but you can serve after cooling at room temperature for 2 hours; bars will be softer.