Cupcakes

1. Preheat the oven to 375°F. Line two 12-cup cupcake tins with liners.
2. In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, and salt.
3. Add the eggs, buttermilk, melted butter, and vanilla extract. Beat on low with a hand mixer until smooth.
4. Stir in the hot coffee with a spatula.
5. Divide the batter evenly among the 24 cupcake liners. Bake for 20 minutes, or until a toothpick inserted in the center comes out clean. Cool completely.

Peanut Caramel Filling

1. Heat the sugar in a medium heavy-bottomed saucepan over medium heat, stirring occasionally, until it melts into a deep amber caramel, about 8–10 minutes.
2. Remove from heat and carefully add the butter (it will bubble). Whisk until melted. Slowly pour in the heavy cream, whisking steadily.
3. Stir in the salt. Return briefly to low heat and stir 1 minute. Remove from heat and let cool to a thick, pourable consistency. Stir in the chopped peanuts.

Buttercream

1. In a double boiler, whisk the egg whites and granulated sugar until the sugar is dissolved and the mixture reaches about 115°F.
2. Transfer to a stand mixer bowl and whip on high with the whisk attachment until stiff, glossy peaks form.
3. Add the sifted powdered sugar and mix until combined.
4. Add the shortening and softened butter all at once. Beat until thick and creamy. If it looks curdled, keep mixing — it will come back together.
5. Beat in the vanilla.
6. Melt the caramel squares with the heavy cream in the microwave in 30-second bursts, stirring after each, until smooth. Cool to room temperature, then fold into the buttercream.

Assemble

1. Cut a hole into the center of each cooled cupcake, being careful not to cut all the way through. Fill each hole with the peanut caramel.
2. Transfer the caramel buttercream to a piping bag fitted with a 1M or 6B tip. Pipe swirls on top of each cupcake.
3. Drizzle with chocolate syrup, top each with a mini candy bar, and sprinkle with chopped peanuts. Store in an airtight container.