**Recipe Adapted from Nikki Gladd at http://www.seededatthetable.com/2009/01/25/chocolate-peanut-butter-cake/**
For the cake:
1/2 cup unsweetened cocoa powder
2 cups all purpose flour
1/2 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
2 sticks unsalted butter, room temp
1 1/2 cups sugar
2 large eggs
2 large egg yolks
1 tsp. vanilla extract
1 cup buttermilk
4 oz. bittersweet chocolate, melted and cooled
2 batches Peanut Butter Frosting
miniature peanut butter cups, halved and/or chopped
For the cake, center a rack in the oven and preheat the oven to 350°. Butter two 9×2” round cake pans, dust the insides with flour, tap out the excess and line the bottoms with rounds of parchment paper. Place the pans on a baking sheet.
In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda and salt. Set aside.
In a stand mixer fitted with the paddle attachment, beat the butter on medium speed until soft and creamy. Add the sugar and beat for about 2 minutes, until thoroughly blended into the butter. Add the eggs and yolks one at a time, beating for one minute after each addition and scraping down the sides of the bowl as needed. Beat in the vanilla. Reduce the mixer speed to low and add the dry ingredients alternately with the buttermilk; add the dry ingredients in 3 additions and the buttermilk in 2 (beginning and ending with the dry ingredients). Mix each addition only until it is blended into the batter. Scrape down the bowl and add the melted chocolate, if using, folding it in with a spatula.Divide the batter between the prepared cake pans.
Bake for 26-30 minutes or until the cakes feel springy to the touch and start to pull away from the sides of the pans. Transfer to wire racks to cool for about 5 minutes, then run a knife around the sides of the cakes, unmold them and peel off the paper liners. Invert and cool to room temperature right side up.
To assemble the cake, place one cake layer on a cardboard circle. Spread peanut butter frosting on top of the cake layer. (If desired, sprinkle with chopped Reese’s cups.) Place the second cake layer on top of the frosting. Frost the top and outside of the cake with remaining peanut butter frosting. Decorate with halved and chopped Reese’s cups as desired.