Make the Cupcakes: Preheat oven to 350 degrees F. Line a standard 12-cup muffin tin with paper or foil liners.
Place the chocolate and cocoa in a medium bowl. Pour the coffee over the mixture and let sit, covered, for 5 minutes. Whisk the mixture gently until smooth, then transfer to the refrigerator to cool completely, about 20 minutes.
Whisk together the flour, sugar, baking soda and salt in a medium bowl.
Whisk the oil, eggs, vinegar and vanilla extract into the cooled chocolate mixture until smooth. Add the flour mixture to the chocolate mixture and whisk until smooth.
Divide the batter evenly among the muffin cups. Bake cupcakes until set and just firm to the touch, 15 to 20 minutes. Let the cupcakes cool in the tin on a wire rack until cool enough to handle, about 10 minutes. Remove each cupcake from the tin, set on the wire rack, and let cool completely before filling and frosting, about 1 hour. (Unfrosted cupcakes can be stored at room temperature for up to 1 day.)
Make the Filling: Beat the marshmallow creme and butter on medium speed until soft and light, about 2 minutes. Reduce the speed to low and slowly 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 pastry bag fitted with a large, round tip (I used an Ateco #804) and refrigerate until ready to use.
Make the Ganache Frosting: Place the chopped chocolate in a small bowl. Place the cream in a small saucepan and bring to a simmer over medium heat. Remove from the stove, and immediately pour over the chopped chocolate. Let stand for 2 minutes, then gently whisk together until a smooth ganache forms. Set aside to thicken for 5 to 10 minutes.
Make the White Icing: Beat together the powdered sugar, butter, milk and vanilla on medium speed until completely blended and smooth. Transfer the icing to a pastry bag fitted with a small, round tip (I used a Wilton #3) and refrigerate until ready to use.
Assemble the Cupcakes: Using a 1-inch round cookie cutter (or the bottom of a large decorating tip), cut the centers out of the cooled cupcakes, going about two-thirds of the way down (just like I did in these cupcakes). Using the prepared pastry bag, pipe filling into the holes of each cupcake. If any filling spills over the top, just scrape it off so the top stays smooth.
Once all of the cupcakes have been filled, take them one at a time and dip them, top-side-down, into the ganache. Dip them down to where the liners starts, so that the entire top is covered. Allow any excess to drip off, then place back on the cooling rack, right-side up. Once all of the cupcakes have been topped with ganache, transfer the cooling rack to the refrigerator for 20 to 30 minutes to allow the ganache to firm up and set.
Once the ganache is firm, take your pastry bag with the white icing and pipe the decorative curls across the top of each cupcake. Allow to set for about 15 minutes before serving. Any leftover cupcakes should be stored in an airtight container in the refrigerator.