Preheat oven to 350 degrees. Grease and flour 2 8" round cake pans.
In a large mixing bowl stir together the flour, sugar, baking powder, salt and cocoa powder.
In a separate bowl whisk together the milk, eggs, vegetable oil, and coffee.
Add the dry ingredients into the wet ingredients. Mix until everything is well combined, about one minute, being sure to scrape down the bottom and sides of the bowl so all the ingredients get mixed properly.
Pour the batter evenly into the two prepared cake pans. Bake 20-22 minutes. The cake is done when a toothpick inserted in the middle comes out clean.
For the Frosting:
Allow the cake to cool for 10 minutes, then turn them out onto a wire rack to cool completely.
Beat together the butter and peanut butter. Once they are smooth, stir in the cocoa powder.
Alternate adding the milk and powdered sugar, reserve some of the milk unless your frosting is not creamy enough.
Assemble the cake:
Place one cake layer down on a cake plate. Frost the top with a thin layer of frosting.
Place the second cake on top. Frost the entire outside of the cake with the chocolate frosting.
Press mini chocolate chips on the outside of the sides of the cake if desired to decorate.
The calories shown are based on the cake being cut into 10 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**