Peanut Butter Fudge Cake
Peanut Butter Fudge Cake combines rich chocolate cake with a creamy peanut butter layer and a smooth fudge frosting. The warm cake absorbs the peanut butter, creating moist, decadent layers. This dessert offers a perfect balance of sweet and nutty flavors. Ideal for any occasion, it delivers comforting, homemade indulgence in every bite.
Equipment
- 9×13 inch baking pan
- Mixing bowls
- Electric mixer or whisk
- Measuring cups and spoons
- Rubber spatula
- Saucepan
- Cooling rack
- Knife or cake spatula for frosting
Ingredients
For the Cake Base
- 2 cups about 250 g all-purpose flour
- 2 cups about 400 g granulated white sugar
- 1 teaspoon baking soda
- 1 cup 226 g unsalted butter (or margarine)
- ½ cup approx. 50 g unsweetened cocoa powder
- 1 cup 240 ml buttermilk
- 2 large eggs beaten
- 1 teaspoon vanilla extract
For the Peanut Butter Layer (middle)
- 1½ cups about 360 g creamy peanut butter
- You can warm it slightly to make spreading easier
For the Fudge / Chocolate Frosting
- ½ cup 113 g butter (or margarine)
- ¼ cup about 25 g unsweetened cocoa powder
- ⅓ cup approx. 80 ml buttermilk
- 4 cups approx. 480 g confectioners’ (powdered) sugar, sifted
- 1 teaspoon vanilla extract
Instructions
Preheat and prepare pan
- Preheat your oven to 350 °F (175 °C). Grease and flour a 9×13 inch (or similarly sized) baking pan, or line it with parchment paper.
Mix dry ingredients
- In a large bowl, combine the flour, granulated sugar, and baking soda. Set aside.
Make chocolate‑buttermilk mixture
- In a saucepan over medium heat, melt the 1 cup (226 g) butter. Stir in the ½ cup cocoa powder until fully combined. Then stir in the buttermilk and the beaten eggs until well blended. Bring it to a gentle boil, stirring constantly. Remove from heat once it begins to bubble. Let it cool just a little.
Combine batter
- Add the chocolate mixture into the dry ingredients, stirring until smooth and no lumps remain. Stir in the 1 teaspoon vanilla. Pour the batter into the prepared baking pan, smoothing the top.
Bake
- Bake for about 20–25 minutes (some recipes say up to 30 minutes) or until a toothpick inserted into the center comes out clean.
Slight cooling & peanut butter layer
- Let the cake cool in the pan for about 10 minutes. While still warm (but not scalding), carefully spread the creamy peanut butter over the top of the cake, covering it nearly to the edges. The residual warmth helps it adhere. Then allow the cake + peanut butter to cool completely (on a wire rack) before frosting.
Make fudge frosting
- In a small saucepan over medium heat, combine the ½ cup butter, ¼ cup cocoa powder, and ⅓ cup buttermilk. Bring to a boil while stirring constantly. Remove from heat, then pour this hot mixture over the sifted powdered sugar in a mixing bowl. Stir until smooth. Add 1 teaspoon vanilla extract and mix well.
Frost the cake
- Spread the fudge frosting over the top of the cooled cake (over peanut butter). Smooth it out with an offset spatula or the back of a spoon.
Slice & serve
- Let the cake rest for a little while to let frosting set (you may refrigerate briefly if desired). Cut into squares and serve.
Notes
1. Substitutions: If you prefer a healthier version, you can use a natural peanut butter with no added sugar. You could also replace the all-purpose flour with a gluten-free blend if you’re looking for a gluten-free option.
For a dairy-free version, swap the butter and heavy cream for dairy-free alternatives like coconut oil and almond milk.
2. Peanut Butter Options: You can use crunchy peanut butter for a different texture. The cake will have a delightful crunch when you bite into it.