Preheat oven to 350 F. In a mixing bowl, combine flour, sugar, and salt. In a saucepan, melt butter. Add cocoa. Stir together. Add hot coffee, allow mixture to boil for 30 seconds, then turn off heat. Pour over flour mixture and stir lightly to cool. In a measuring cup, combine the buttermilk, beaten eggs, baking soda, and vanilla. Stir buttermilk mixture into butter/chocolate mixture. Pour into cake pans and bake at 350-degrees for 30-40 minutes. They are done when a toothpick comes out clean or the middle firms up and springs back when lightly pressed.

For the frosting, cut the butter into pieces then, in the bowl of an electric stand mixer fitted with the paddle attachment, whip the butter until pale and fluffy, about 5-7 minutes.

Add the peanut butter and mix until smooth and incorporated.

Mix in 2 cups of powdered sugar and mix on low until incorporated. Add the whiskey and vanilla, mix to combine. Add two more cups of powdered sugar beat on low until combined then increase the speed to medium-high for 3 minutes. If necessary, add more powdered sugar ¼ cup at a time until the frosting reaches the desired consistency.

Add up to 1 Tbsp. of whole milk if the frosting becomes too stiff.

Assemble the cake by placing one layer on the cake pan. If desired, level off each cake round with a serrated knife (cut off the dome) but this cake is heavy and I found this step to be unnecessary for this cake.

Pipe a spiral of frosting across the cake, sprinkle with chopped peanut butter cups and repeat with each layer (except do not sprinkle the peanut butter cups on the top layer).

Using an offset spatula, level the frosting on the top layer as desired. Smudge frosting around the edges and smooth off for a naked rustic look.

Garnish the top with a pile of chopped peanut butter cups.

Dig in!