• Preheat the oven to 350℉/180℃ and line a muffin tin with cupcake liners.

Graham Cracker Crust

• Pulverize the graham cracker crumbs into a fine powder, then mix it together with the melted butter, sugar, and salt until completely moistened.
  1 cup graham cracker crumbs, ¼ cup unsalted butter, 1 tablespoon granulated sugar, ⅛ teaspoon kosher salt
• Add one heaping tablespoon of crumbs to each cupcake liner, then press it down to compact it completely.

Chocolate Cupcakes

• Sift together the flour, sugar, cocoa powder, baking soda, baking powder, and salt.
  ¾ cup all-purpose flour, ¾ cup granulated sugar, ⅓ cup cocoa powder, ¾ teaspoon baking soda, ½ teaspoon baking powder, ¼ teaspoon kosher salt
• In a separate bowl, mix together the egg, sour cream, vegetable oil, and vanilla with a whisk until combined.
  1 large egg, ⅓ cup sour cream, ⅓ cup vegetable oil, ½ teaspoon vanilla extract
• Add the wet ingredients to the dry ingredients and mix together with a wooden spoon or rubber spatula. Add the hot coffee or water and carefully stir to combine.
  ½ cup hot coffee or water
• Fill each cupcake liner ⅔ full, and bake for 13-15 minutes. The top of the cupcake will spring back when touched. A toothpick inserted into the center will come out clean with a few moist crumbs.
• Cool completely on a wire rack. Once cool, use a cupcake corer to remove the filling or the bottom of a round wooden spoon to push down the filling to make a hole in the center of each cupcake.
• Transfer the marshmallow fluff to a piping bag and fill the center of each cupcake with filling to the top.
  ½ cup marshmallow fluff

Graham Cracker Frosting

• Combine graham cracker crumbs and heavy cream and mix to moisten significantly.
  1 cup graham cracker crumbs, ¼ cup heavy whipping cream
• Beat together the butter and powdered sugar with the paddle attachment of a stand mixer (or use a hand mixer) on medium speed for 3 minutes until airy.
  ½ cup unsalted butter, 2 cups powdered sugar
• Add the wet graham cracker crumbs and mix to combine.
• Add the remaining heavy cream and beat on medium high speed until light and fluffy. Add more cream if it feels too dense to pipe.
  2-3 tablespoons heavy whipping cream

Assembly

• *Add the graham cracker buttercream to a large piece of plastic wrap in a log, then add the marshmallow fluff in a line next to it (fluff is optional).
  ⅔ cup marshmallow fluff
• Roll it up, then add the log to a piping bag. Snip off ¾" from the tip, then pipe the frosting on in a swirl on top of each cupcake.