Chocolate Peanut Butter Fudge Cake

8 servings Prep: 20 m Cook: 30 m Total: 50 m Intermediate
This is my mother-in-law’s Ginger Comeaux’s recipe for my husband’s birthday cake. A rich chocolate cake with chocolate fudge frosting and a layer of peanut butter in between—it’s pure indulgence with cocoa, butter, pecans, and that sweet-salty peanut butter surprise.

Ingredients

  • 2 cups flour
  • 2 cups sugar
  • dash of salt
  • 1/2 tsp baking soda
  • 1 cup water
  • 2 sticks butter
  • 4 tsp cocoa
  • 2 eggs
  • 1/2 cup buttermilk
  • 1 tsp vanilla
  • 4 tsp cocoa
  • 6 tbsp milk
  • 1 stick butter
  • 1 box powdered sugar
  • 1/2 cup pecans diced
  • peanut butter for cake

Step-by-Step Instructions

  1. Preheat oven to 350°F. Spray a 13x9-inch baking dish with nonstick cooking spray.
  2. Cake: In a bowl mix the 2 cups flour, 2 cups sugar, salt (a dash/optional), and 1/2 tsp baking soda.
  3. In a pot mix and bring to a boil 1 cup water, 2 sticks butter, and 4 tsp cocoa.
  4. In another bowl mix the 2 eggs, 1/2 cup buttermilk (if you don’t have any in the house mix 1/2 cup milk, 1 tsp lemon juice, and 1 tsp vinegar and mix well), and 1 tsp vanilla.
  5. Now mix all the ingredients together and put in the prepared baking dish. Bake at 350°F for 30 to 45 minutes. Do the cake test by inserting a toothpick in the center—if it comes out clean the cake is done. Cool completely before frosting.
  6. While cake is cooling make the frosting: In a pot mix and bring to a boil the 4 tsp cocoa, 6 tbsp milk and 1 stick butter. Remove from heat and add a box of powdered sugar, mixing well. Stir in the diced pecans.
  7. Once cake is completely cooled, spread a layer of peanut butter over the top, then pour the warm frosting over the peanut butter layer.
  8. Serve with a nice cup of Community Coffee, Mellow Joy or whatever your favorite blend is.

Common Problems and Solutions

Q: Why did my cake turn out dry?

A: Make sure you're doing the toothpick test and not overbaking. The recipe gives a range of 30-45 minutes because ovens vary—start checking at 30 minutes. Also, cooling the cake completely before adding the peanut butter layer keeps moisture in.

Q: Can I use natural peanut butter for the middle layer?

A: Regular creamy peanut butter works best because it spreads more easily and has a smoother consistency. Natural peanut butter can be oily and may not layer as nicely, but it will still taste good if that's what you have.

Tips and Techniques

Don’t skip cooling the cake completely before adding the peanut butter layer—if the cake is even slightly warm, the peanut butter will melt and mix with the frosting instead of staying as a distinct layer. The buttermilk substitute (milk + lemon juice + vinegar) works perfectly if you don’t keep buttermilk on hand.

Ingredient Substitutions

  • buttermilk: 1/2 cup milk + 1 tsp lemon juice + 1 tsp vinegar
  • pecans: walnuts or chopped peanuts

Equipment Needed

  • 13x9-inch baking dish
  • mixing bowls
  • saucepan or pot
  • toothpick for testing doneness

Historical Context

The peanut butter and chocolate combination became popular in Southern baking after Reese’s Peanut Butter Cups debuted in 1928. Home bakers started adding peanut butter layers to chocolate cakes for birthday celebrations, creating their own versions of this beloved flavor pairing.