When I first saw this recipe on Bakerella, I just knew I had to try it. I love peanut butter cups and chocolate, so the rich chocolate and peanut butter of this dessert sounded delicious. It did not disappoint! The only change I made to the recipe was in adding the icing. Rather than spreading the ganache icing on the sides of the cake, I allowed it to drip over the sides for a different look.
1 box Duncan Hine's devil's food cake mix
1 cup buttermilk
1/2 cup vegetable oil
2 cups chopped Reese's peanut butter cups (about 8 ounces), plus more to garnish
8 ounces dark chocolate, chopped
1 cup heavy cream
1/2 cup creamy peanut butter
Heat oven to 350 degrees. Coat two 9-inch round cake pans with nonstick cooking spray. Trace the pan on wax paper and cut out a round to fit into the bottom of each pan. Lay wax paper circle in the bottom and coat paper with another layer of nonstick cooking spray.
In a large bowl, beat cake mix, eggs, buttermilk and vegetable oil on low for 30 seconds. Increase speed to medium-high; beat for 2 minutes, scraping down side of the bowl after 1 minute. Fold in 2 cups of the chopped peanut butter cups.
Divide batter between prepared pans. Bake at 350 degrees F for about 34 minutes, or until a toothpick inserted in the center comes out clean. Let layers cool on a wire rack for 15 minutes. Turn out cakes onto wire racks, peel off the wax paper, and cool completely.
Place chopped dark chocolate in a medium-size bowl. Bring cream just to a boil and pour over chocolate. Whisk until chocolate melts. Add peanut butter and whisk until smooth.
Put 1 cake layer on the serving dish or cake plate. Pour 1 cup frosting on top; spread evenly with a spatula. Top with remaining cake layer. If your cakes are really rounded on top, you may need to trim top off with a serrated knife to flatten. Pour remaining frosting over the top, allowing it to spill over the sides. Smooth top and with a spatula, allowing extra to run down the sides. Refrigerate 1 hour to set. Garnish with chopped candy, if desired.
*Note, the 1 hour refrigeration step is important to keep the top layer from sliding off the bottom layer, especially if you are going to travel with the cake!
You can also use 2 six inch pans, and make 8 cupcakes, with the batter. Use 2 cups of batter in each 6 inch pan, and fill 8 cupcake liners 3/4 full.