Chocolate Ganache

1. Place the chopped chocolate in a heat safe bowl.
2. Place the heavy cream in a smaller heat safe bowl and microwave for 10 second intervals, stirring in between until the cream is hot.
3. Pour the cream over the chocolate and stir until combined. Reheat for 10 seconds if the chocolate isn't fully melted.
4. Let cool before covering with plastic wrap and placing in the fridge to chill.

Chocolate Cupcakes

1. Preheat oven to 350º F.
2. In a large bowl, whisk together the flour, baking soda, baking powder, cocoa powder, and salt and set aside.
3. In a stand mixer fitted with a paddle attachment, combine the butter and sugar for 2-3 minutes on medium speed until light and fluffy.
4. Add eggs, one at a time, scraping down the sides of the bowl with your spatula as needed. Add vanilla.
5. With the mixer on low, add the buttermilk.
6. Beginning and ending with the flour mixture, alternate between adding the flour mixture and the coffee to the batter. Scrape down the sides of the bowl as needed.
7. Using a 2 tablespoon cookie scoop, carefully scoop 2 tablespoon of batter into each cupcake liner. Scrape down the sides of the bowl and split the remaining batter among the cupcakes until they look even.
8. Bake for 22-24 minutes until a toothpick inserted in the center comes out clean.
9. Let the pan cool on the cooling rack for 15 minutes before gently pulling the cupcakes out of the pan and letting them cool completely on the cooling rack.

Marshmallow Topping

1. Once the cupcakes are cooled, stir together the egg whites, sugar, and cream of tartar in a double boiler. Continue to stir constantly until mixture reaches 160º F on a candy thermometer.
2. Transfer to a mixing bowl, add in the vanilla, and mix with the whisk attachment on medium-high speed for 3-4 minutes followed by high speed for another 4-5 minutes until stiff peaks have formed.

Assembly

1. Use a cupcake corer or a small knife to carefully cut the center of each cupcake. Save the tops that you cut out as these will be added back.
2. Add the chocolate ganache to a pastry bag and carefully pipe into the centers of each cupcake until they're ¾ full. If your ganache is too thick, carefully reheat in the microwave for 10 seconds until it is a better piping consistency.
3. Gently add the tops back so they cover up the chocolate ganache.
4. Scoop the meringue into a pastry bag fitted with an Ateco 807 or similar piping tip.
5. Starting in the middle of the cupcake, hold the piping bag upright and apply pressure to pipe straight down until a dollop of meringue almost reaches the borders. Gently lift up in a swift swirling motion to leave a slight tip.
6. Repeat this with the remaining cupcakes. Enjoy!