What You’ll Need
* For the cake:
* 2 cups all-purpose flour
* 2 cups granulated sugar
* 1 teaspoon baking soda
* 1 cup unsalted butter
* 1/4 cup unsweetened cocoa powder
* 1 cup water
* 1/2 cup buttermilk
* 2 large eggs, lightly beaten
* 1 teaspoon vanilla extract
* 16 ounces (about 1 & 1/2 cups) creamy peanut butter
* For the icing:
* 1/2 cup unsalted butter
* 1/3 cup buttermilk
* 1/4 cup unsweetened cocoa powder
* 16 ounces confectioners’ sugar, sifted
* 1 teaspoon vanilla extract
How to Make It
* 1 _ Preheat oven to 350°. Grease and flour a 9” x 13” baking pan.
* 2 _ Whisk together flour, sugar, and baking soda in a large bowl. Set aside.
* 3 _ Place butter in a medium saucepan. Melt over medium heat.
* 4 _ Stir in cocoa powder. Then, stir in water, buttermilk, and eggs. Continue cooking over medium heat, stirring constantly, until the mixture boils.
* 5 _ Remove the mixture from the heat and add to flour mixture. Stir until smooth. Stir in vanilla.
* 6 _ Transfer batter to prepared pan and spread evenly.
* 7 _ Bake 20 to 25 minutes, or until a pick inserted into the center of the cake comes out clean.
* 8 _ Cool in pan on wire rack for 10 minutes. Then, spread the peanut butter over the cake. Allow to cool completely.
* 9 _ To make the icing, place the sifted confectioners’ sugar in a large bowl. Set aside.
* 10 _ Combine butter, buttermilk, and cocoa in a small saucepan. Cook over medium heat, stirring constantly, until the mixture begins to boil.
* 11 _ Remove from heat and pour over confectioners’ sugar. Stir until smooth. Stir in vanilla.
* 12 _ Spread icing over peanut butter. The cake can be served immediately or can sit at room temperature to allow the icing to set.