Sift the flour, sugar, cocoa, baking soda, baking powder, and salt into the bowl of an electric mixer fitted with a paddle attachment and mix on low speed until combined.

In another bowl, combine the buttermilk, oil, eggs, and vanilla.

With the mixer on low speed, slowly add the wet ingredients to the dry. With mixer still on low, add the coffee and stir just to combine, scraping the bottom of the bowl with a rubber spatula.

Pour the batter into the prepared pans and bake for 35 to 40 minutes, until a cake tester comes out clean.

Cool in the pans for 30 minutes, then turn them out onto a cooling rack and cool completely.

In the bowl of a stand mixer, beat the butter and peanut butter on high speed for 1 minute.

Scraping down the sides of the bowl, add the icing sugar, vanilla and dash of milk, beating until light and fluffy, about 3 minutes.

Add one half of the chopped peanut butter cups on top of the frosting, pressing down into the frosting.

Add the second layer, frost, fill with peanut butter cups.

Add the final layer of cake, frosting the top and sides to a crumb coat.

Chill in freezer for ten minutes to set crumb coat.

Frost a final coat of peanut butter frosting and set aside.

Using a bain-marie or heatproof bowl set on top of boiling water, melt together the butter and chocolate.

Mix together slowly with a wooden spoon.

Set aside to cool for 20 minutes; it will thicken slightly. Pour on top of peanut butter frosting covered cake, using an offset spatula to gently ice the glaze to the edges of the cake for maximum dripping.

Top the cake with chopped Reese’s peanut butter cups, meringue kisses, chocolate shards or sprinkles.