Prepare the Cupcake Base:

• Preheat oven to 350°F (175°C) and line a muffin tin with cupcake liners.

• Mix flour, cocoa powder, and baking powder. Set aside.

• Beat butter and sugar until creamy (2-3 minutes).

• Add eggs one at a time, mixing well after each.

• Alternate adding dry ingredients and milk, mixing until combined.

• Fill cupcake liners halfway with batter.

Assemble the Marshmallow Filling:

• Use a spoon to make a small hole in the center of each cupcake.

• Spoon marshmallow fluff into each hole, being generous but careful not to overfill.

Bake and Cool:

• Bake for 18-20 minutes, testing with a toothpick to check for doneness.

• Cool cupcakes in the tin for 5 minutes, then transfer to a wire rack.

Prepare the Toppings:

• Heat heavy cream in a small saucepan, then pour over chopped chocolate to make the ganache.

• Spoon ganache onto each cooled cupcake.

• Sprinkle with graham cracker crumbs and top with mini marshmallows.

• Toast marshmallows with a kitchen torch or under the broiler for a few seconds.