01 -
Preheat the oven to 350F. Spray the inside of three 6-inch cake pans with nonstick spray and line the bottoms with parchment paper. Fit the pans with cake strips if using.
02 -
Stir together the milk and vinegar in a measuring glass and set aside.
03 -
In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
04 -
In a large mixing bowl, whisk together the sugar, oil, eggs, and vanilla extract. Add the milk and vinegar mixture and mix until combined.
05 -
In another measuring glass, mix together the hot water and espresso powder.
06 -
Add the dry ingredients to the wet ingredients and whisk until nearly combined. Pour in the hot coffee mixture and continue whisking until smooth.
07 -
Divide the batter evenly between the prepared pans and bake for 35-40 minutes. Remove from the oven when a toothpick inserted comes out with a few moist crumbs. Cool the cakes for 15 minutes in the pans, then transfer to a cooling rack.
08 -
In a large bowl, use a mixer to beat the butter and peanut butter until smooth. Gradually mix in the powdered sugar, followed by the milk one tablespoon at a time until smooth and creamy.
09 -
Level the cake tops and slice each layer in half to create 6 layers total. Spread approximately 3/4 cup of frosting between each layer and smooth the edges for a naked cake effect.
10 -
Transfer the assembled cake to the refrigerator to chill while preparing the ganache.
11 -
Microwave the heavy cream until steaming and pour over chopped chocolate. Let sit for a couple of minutes before whisking until smooth. Chill for 15 minutes until slightly thickened.
12 -
Test the ganache by dripping a spoonful down the cake. If ready, pour the ganache around the edges, let it drip, and return the cake to the refrigerator for 10 minutes. Arrange peanut butter cups and chopped peanuts on top.