Step 1: Prepare the Cake Batter

1. In a large mixing bowl, sift together 1 ¾ cups all-purpose flour, ⅔ cup unsweetened Hershey’s cocoa powder, 1 ½ tsp baking powder, and 1 ½ tsp baking soda to remove lumps.

2. Whisk in ½ tsp salt and 2 cups granulated sugar until evenly combined.

3. Add 1 cup buttermilk, 2 tsp pure vanilla extract, and ½ cup + 2 tbsp vegetable oil. Whisk until smooth and fully incorporated.

4. Add 2 large eggs, one at a time, whisking well after each addition until the batter is cohesive.

5. Carefully whisk in 1 cup boiling water, stirring slowly to avoid splashing, until the batter is thin and smooth. The batter will be runny, which is normal for this recipe.

   • Tip: Sift dry ingredients to ensure a smooth batter. Use room-temperature eggs for better emulsification. Add boiling water gradually to prevent curdling. Whisk gently to avoid overmixing, which can affect texture.

Step 2: Prepare the Slow Cooker

1. Lightly grease a 6-quart slow cooker insert with cooking spray or a thin layer of butter to prevent sticking.

2. For easier removal, line the slow cooker with a parchment paper sling (two long strips crossed, overhanging the edges) and lightly spray the parchment.

3. Pour the batter into the slow cooker, spreading it evenly with a spatula.

   • Tip: Use a slow cooker liner or parchment sling for easy cleanup and removal. Ensure the batter is level to promote even cooking. A 6-quart slow cooker is ideal for this volume.

Step 3: Slow Cook

1. Cover and cook on high for 2.5-3.5 hours or low for 4-5 hours, until a toothpick inserted in the center comes out clean or with a few moist crumbs.

2. Check doneness at the minimum time; if the center is too wet, continue cooking in 15-minute increments. If the top looks too moist, remove the lid for the last 15-20 minutes to evaporate excess moisture.

   • Tip: Place a paper towel or clean dish towel under the lid to catch condensation and prevent a soggy surface. Avoid lifting the lid too often to maintain heat. Cooking times vary by slow cooker model.

Step 4: Cool the Cake

1. Turn off the slow cooker and let the cake cool in the insert for 10-15 minutes to set slightly, making it easier to remove or serve.

2. Use the parchment sling (if used) to lift the cake out, or scoop portions directly from the slow cooker. Transfer to a serving platter if slicing, or serve warm from the slow cooker for a rustic presentation.

   • Tip: Cool slightly before frosting to prevent melting. If serving warm, scoop directly for a cozy, fudgy experience.

Step 5: Prepare the Chocolate Frosting

1. In a medium mixing bowl, use a handheld mixer or stand mixer on medium-high speed to beat 1 cup softened salted sweet cream butter and 1 tsp pure vanilla extract for 1-1 ½ minutes, until light and fluffy.

2. Add ⅔ cup unsweetened Hershey’s cocoa powder and mix on low speed until combined.

3. Add 3 cups powdered sugar, ½ cup at a time, alternating with ¼ cup + 2 tbsp whole milk, beating until fully incorporated and the frosting is smooth and spreadable.

4. Increase the mixer speed to medium-high and beat for 1 minute until fluffy.

   • Tip: Soften butter at room temperature for easier beating. Sift powdered sugar to avoid lumps. Adjust milk for a spreadable or pipeable consistency; add more for a thinner frosting.

Step 6: Assemble and Serve

1. Spread or pipe the chocolate frosting over the cooled or slightly warm cake using a spatula or a piping bag with a round or star tip. For piping, swirl in a circular pattern for a decorative look.

2. Slice the cooled cake into 8-10 squares or wedges, or scoop warm portions into bowls or dessert cups (about ½ cup per serving).

3. Serve at room temperature for a classic cake texture or warm for a fudgy, indulgent experience. Pair with coffee, milk, or a dessert liqueur (like Baileys) for a decadent vibe.

   • Tip: Spread frosting evenly for a polished look or pipe for flair. Serve in shallow bowls if scooping warm, or on plates if slicing cooled. Garnish with chocolate shavings or sprinkles for extra appeal.