Combine all the dry ingredients together in a large bowl and whisk until combined, set aside.
Whisk together, eggs, buttermilk, oil and vanilla until well combined. Add the egg mixture to the dry ingredients and whisk, while slowly adding the coffee and rum to the batter and whisk until totally blended and smooth, about 2 minutes. The batter will be quite runny.
Spread batter evenly over the greased and lined baking sheet, and bake at for about 20-25 minutes or until set.
Make the buttercream: Cream together the sugar, butter, vanilla, and almond extract and beat slowly until smooth.
Blend the buttercream, cocoa, melted chocolate, devil’s food scraps, and peanut butter until smooth. Add heavy whipping cream until spreadable. You may need a little bit more heavy cream to make up for the cake in the buttercream.
To assemble and crumb coat the cakes: Spread about 3 tablespoons of the buttercream over half the cake circles. Sandwich the buttercream with the remaining cake circles. Frost the tops and sides of the cakes with the remaining buttercream, then refrigerate the cakes to set.
Make the ganache: Heat the cream to a simmer, add the chocolate, swirl them together. After about 3 minutes, gently whisk until smooth. Let the ganache cool slightly, so it is still pourable, but thick enough to coat the cakes in a thick layer.
Place the chilled cakes on a clean cooling rack, set over a baking sheet lined with parchment paper. Pour the warm ganache over the top of the cakes to fully cover them. Let the ganache set on the cakes for about 45 minutes.
Chop the peanuts into fine pieces and press them to the sides of the cakes. Serve immediately or refrigerate for up to a day. I like them served at room temperature.