For the chocolate cake layers

1. Preheat oven to 350°F (176°C) and prepare three 8 inch cake pans with non-stick baking spray and parchment paper in the bottom.
2. Add the flour, sugar, cocoa, baking soda, baking powder and salt to a large mixer bowl and combine. Set aside.
3. Add the milk, vegetable oil, vanilla extract and eggs to a medium sized bowl and combine.
4. Add the wet ingredients to the dry ingredients and beat until well combined.
5. Slowly add the hot water to the batter and mix on low speed until well combined. Scrape down the sides of the bowl as needed to make sure everything is well combined.
6. Divide the batter evenly between the prepared cake pans and bake for 22-25 minutes, or until a toothpick comes out with a few moist crumbs.
7. Remove cakes from oven and allow to cool for 2-3 minutes, then remove to a cooling rack to finish cooling.

To make the frosting

1. Combine the butter and peanut butter in a large mixer bowl and mix until well combined.
2. Add about half of the powdered sugar and mix until smooth.
3. Add 3 tablespoons of water or milk and mix until smooth.
4. Add remaining powdered sugar and mix until smooth.
5. Add remaining water or milk and mix until smooth, keeping an eye on the consistency of the frosting so it doesn’t get too thin.

To build the cake

1. Use a large serrated knife to remove the tops of the cake layers so that they’re flat. See my tips on how to level a cake and how to stack a cake.
2. Place the first cake layer on a serving plate or cardboard cake circle and top with about 1 cup of frosting. Smooth frosting into an even layer.
3. Add about half of the chopped Reese’s on top of the frosting and press into the frosting. Spread a small amount of frosting on top of the Reese’s so that it’s sticky on top for the next cake layer.
4. Add the next cake layer and top with about 1 cup of frosting. Smooth frosting into an even layer.
5. Add remaining half of the chopped Reese’s on top of the frosting and press into the frosting. Spread a small amount of frosting on top of the Reese’s so that it’s sticky on top for the next cake layer.
6. Add the final cake layer to the top of the cake.
7. Smooth out the frosting on the sides of the cake, creating a thin crumb coat.
8. Add about 1 cup of frosting to the top of the cake and smooth into an even layer.
9. Frost the cake using my tutorial for a smooth cake. Stop just before using the paper towel, which won’t be necessary with the pattern on the sides of this cake.
10. Use an offset spatula to create the stripes around the cake. For guidance, see the video above starting at about 1:40.
11. Set the cake aside and make the chocolate ganache (see my tips for making chocolate ganache).

Make the ganache and decorate

1. Put the chocolate chips in a heat proof bowl.
2. Microwave the heavy whipping cream until it just begins to boil, then pour it over the chocolate chips. Allow it to sit for 2-3 minutes, then whisk until smooth.
3. Use a squeeze bottle or a spoon to drizzle the chocolate around the edges of the cake, then fill in the top of the cake and smooth it with an offset spatula. See my tips for making a chocolate drip cake.
4. Allow the ganache to firm a bit, about 10 minutes, then top with swirls of the remaining frosting. Use a piping bag fitted with a closed star tip. I used Ateco tip 844, but Wilton 2D or 1M would work as well. Then top with additional Reese’s chopped in half, and Reese’s crumbles.
5. Refrigerate the cake until ready to serve. Serve at room temperature. Cake is best for 3-4 days.