Preheat the oven to 350°F. Line a 12-cup muffin tin with liners.

In a bowl, mix the chopped chocolate and cocoa powder. Pour the hot coffee over the mixture, cover it for 5 minutes, and then cool it down.

In another bowl, whisk together the bread flour, granulated sugar, baking soda, and salt.

Mix the vegetable oil, eggs, white vinegar, and vanilla extract into the cooled chocolate mixture until smooth.

Combine the flour mixture with the chocolate mixture until it is smooth.

Pour the batter into the muffin cups and bake for 15-20 minutes.

Let them cool for 10 minutes, then transfer them to a wire rack to cool completely.

For the filling, beat the marshmallow creme and softened butter together. Gradually add powdered sugar until the mixture is fluffy.

For the ganache, heat the heavy cream and pour it over the chopped chocolate. Whisk until smooth and let it thicken.

For the icing, mix the remaining powdered sugar, butter, milk, and vanilla extract until smooth.

Fill the cooled cupcakes with the marshmallow filling. Dip the tops into the ganache, let it set, and then pipe the icing on top.