| Chocolate Cake
|Preheat oven to 325º F. Place cupcake liners in muffin tin.
Add flour, sugar, cocoa, baking powder, baking soda, and salt to a large bowl of a stand mixer. Using paddle attachment, stir through flour mixture until combined well.
Add milk, vegetable oil, egg, and vanilla to flour mixture and mix together on medium speed until well combined. In a microwave safe glass, heat water until boiled. Remove from microwave and add espresso powder and mix well. With mixer on low speed, carefully add boiling water to the cake batter. Increase to high speed for about 1 minute to add air to the batter.
Evenly distribute cake batter. Each cupcake liner should be about 3/4 full. Bake in the oven until a toothpick inserted in the center comes out clean, about 12-15 minutes. Remove from the oven and allow the cupcakes to cool completely.
| Creme Filling
|Add marshmallow creme and butter in a mixing bow and beat with hand mixer on medium speed until super soft and airy. Reduce the speed to low and carefully add the powdered sugar. Once it has all been incorporated, increase the speed to medium-high and beat for an additional 1 to 2 minutes, or until very light and fluffy. Transfer the filling to a piping bag fitted with a large, round tip and refrigerate until ready to use.
| Chocolate Glaze
|Place the chopped chocolate in a round bowl. Microwave the heavy cream until it comes to a simmer (about 1-1/2 mins, watch it carefully). Remove the cream and pour over the chopped chocolate. Let stand for a minute, then carefully whisk together until a smooth ganache forms. Allow it to thicken for ~5 mins.
| Swirl Icing
|Beat together all icing ingredients on medium speed until completely blended and the texture is smooth and creamy. Transfer the icing to a piping bag with a small writing tip and set aside.
| Assemble the Cupcake
|Once the cupcakes have cooled, cut a circle into the cupcake at an angle to make a “cone” (like in the picture above). Using the prepared piping bag, pipe filling into the holes of each cupcake.
Put the cake top back into the crème filled center (you can remove a little cake from the cake top if you wish). With a clean gloved hand (or offset spatula), press to seal the cupcake. You’ll want to really pack down the cone to make sure it is sealed back into the cupcake. Dust off any crumbs on top so they don’t interfere with ganache coating.
If any filling spills over the top, just scrape it off so the top stays smooth.
Once all cupcakes are filled, stir your ganache to make sure it's perfectly smooth. Re-heat for 5-10 seconds if needed. Take each cupcake one at a time and dip them, tops first into the ganache. Tap to allow access to drip off, then place back on the cooling rack, right-side up. If the ganache isn’t perfect, hold the cupcake and gently shake it side to side and tap it so the ganache will look flawless.
Once all of the cupcakes have been topped with ganache, transfer the cooling rack to the refrigerator for 15 minutes to allow the ganache to firm up and set.
When ganache is firm, get the swirl icing and pipe the signature swirls across each cupcake. Allow to set until firmed and serve or store in an airtight container in the fridge for up to 3 days.