Ingredients
CAKE:
Nonstick vegetable oil spray
3 cups all purpose flour
2 cups sugar
2/3 cup sifted natural unsweetened cocoa powder (sifted, then measured)
2 teaspoons baking soda
1 teaspoon salt
2 cups water
2/3 cup vegetable oil
2 tablespoons apple cider vinegar
2 teaspoons vanilla extract
FILLING:
8oz semi-sweet chocolate, roughly chopped
8oz heavy cream
1/2 cup creamy peanut butter
1/2 cup Reese’s peanut butter cups, roughly chopped
FROSTING:
1/2 cup creamy peanut butter
1/2 cup butter, at room temperature
2 tsp vanilla extract
2 cups powdered sugar
Preparation
CAKE: Preheat oven to 350°F. Spray two 9-inch-diameter cake pans with 2-inch-high sides with nonstick spray. Line pan bottoms with parchment paper. Sift flour, sugar, cocoa, baking soda, and salt into large bowl. Whisk 2 cups water, oil, vinegar, and vanilla in medium bowl to blend. Gradually add water mixture to dry ingredients, whisking until batter is smooth. Divide batter between prepared pans (scant 3 cups each).
Bake cakes until tester inserted into center comes out with a few crumbs still attached, about 28 minutes. Cool cakes in pans 15 minutes. Cut around cakes and turn out onto racks. Peel off parchment and cool.
FILLING: Heat the cream until it just begins to boil. Pour it over the chocolate in a medium bowl. Whisk until the chocolate melts, then whisk in the peanut butter until it’s all incorporated and smooth. Set aside 1/4 of the filling for the first layer of frosting. Cool the other 3/4 completely, then gently stir in the peanut butter cups.
FROSTING: Cream together the butter and peanut butter. Add the vanilla, then the sugar. I beat mine until it was pretty fluffy.
ASSEMBLY: Place one 9-inch round on a cake stand or plate. Cover the top in the peanut butter fudge filling. Place the second 9-inch round on top. Using the reserved filling, spread a thin layer on the outside of the cake. Refrigerate until the fudge is set and firm to the touch.
Slather the whole thing in the peanut butter frosting. Decorate with peanut butter cups.
