Preheat the oven to 350° F. prepare 4, 8-inch round cake pans with cooking spray. Set aside.

In a medium mixing bowl, combine the flour, cocoa powder, baking powder and salt with a whisk. Set aside.

In a separate large mixing bowl with a hand mixer, beat the butter, oil, and sugar until smooth and fluffy. Add the eggs, mix until combined.

Add the dry mixture, alternating with the milk until completely combined.

Divide the batter evenly into the 4 cake pans and spread into an even layer with a spatula.

Bake for 20-25 minutes or until a toothpick can be inserted and come out clean.

Allow the cakes to cool completely while making the frosting.

For the frosting: In a large mixing bowl with a hand mixer, beat the softened butter and peanut butter until smooth and creamy. Gradually add the powdered sugar until completely combined.

For the chocolate ganache: Add the chocolate chips to a heat proof bowl.
In a separate bowl, microwave the heavy cream until it begins to boil.

Pour the hot cream over the chocolate chips and allow to sit for a few minutes to melt the chocolate. Mix until smooth and combined.

Allow the ganache to cool for at least 10 minutes before using.

Assemble: Use a large serrated knife to level the cakes and create an even surface. Stack the cakes with a layer of frosting between each cake layer. Use a large icing spatula to spread a thin even layer of frosting on top of and around the cake to create a crumb coat. Place the cake in the freezer for at least 15 minutes to set the crumb coat. Frost the entire cake with the remaining frosting.

Pour the ganache over the top of the cake and spread into an even layer, allow some ganache to drip down the sides. You can use a squeeze bottle or piping bag to get a cleaner drip.

If desired, you can decorate with extra frosting and reese’s peanut butter cups. Slice and enjoy!