Ingredients

1¾ cups all-purpose flour

¾ cup unsweetened cocoa powder

1 cup granulated sugar

½ cup light or dark brown sugar

2 eggs, room temperature

½ cup vegetable oil or melted butter

1 cup buttermilk or milk with 1 tbsp vinegar

1 cup hot coffee, slightly cooled

2 tsp vanilla extract

1½ tsp baking soda

1½ tsp baking powder

½ tsp salt

1 tbsp mayonnaise (optional for extra moisture)

1 cup creamy peanut butter or crunchy if preferred

½ cup softened butter

2½ cups powdered sugar

2–4 tbsp heavy cream, adjust for consistency

1 tsp vanilla extract

1 pinch salt (optional)

½ cup mini chocolate chips (for garnish or mix-in)

½ cup chopped peanuts (for texture)

¼ cup chocolate ganache (for drizzling)

½ cup crushed peanut butter cups (for topping)

Instructions

Prep Oven & Pans: Preheat the oven to 350°F. Grease two 9-inch cake pans and line the bottoms with parchment paper.

Mix Dry Ingredients: In a large bowl, whisk together the flour, cocoa powder, granulated sugar, brown sugar, baking soda, baking powder, and salt.

Mix Wet Ingredients: In a separate bowl, whisk the eggs, vegetable oil (or melted butter), buttermilk (or milk with vinegar), vanilla extract, and mayonnaise if using.

Combine Wet & Dry: Gradually add the wet ingredients to the dry ingredients, stirring gently until combined. Then stir in the hot coffee until the batter is smooth.

Bake the Cake: Divide the batter evenly between the prepared pans. Bake for 28–32 minutes or until a toothpick inserted in the center comes out clean.

Cool the Layers: Let the cakes cool in the pans for 10 minutes, then transfer them to wire racks to cool completely.

Make Peanut Butter Frosting: Beat the softened butter until fluffy. Add the peanut butter and beat until smooth. Gradually add powdered sugar, then heavy cream a tablespoon at a time until you reach the desired consistency. Stir in vanilla extract and a pinch of salt if using.

Assemble & Decorate: Place one cake layer on a serving plate and spread a layer of frosting on top. Add the second cake layer and frost the top and sides. Garnish with mini chocolate chips, chopped peanuts, drizzle chocolate ganache, and sprinkle crushed peanut butter cups for extra texture and flavor.

Tips & Variations

For a more intense chocolate flavor, use dark cocoa powder and consider adding a handful of espresso powder to the batter.

You can swap the mayonnaise with Greek yogurt or sour cream for a slightly tangy moistness.

Add extra crushed peanut butter cups between layers for an added surprise.

Use crunchy peanut butter if you prefer more texture in the frosting.

FAQs

Can I make this cake gluten-free?

Yes, you can substitute the all-purpose flour with a gluten-free flour blend that measures cup-for-cup. Ensure the blend contains xanthan gum or add it separately to maintain texture.

Can I prepare the cake layers in advance?

Absolutely. You can bake the cake layers a day or two ahead, wrap them tightly in plastic wrap, and refrigerate. Bring them to room temperature before frosting and assembling.