For the crust: Preheat the oven to 325 degrees F. Line muffin pans with 36 muffin liners. Combine the graham cracker crumbs, granulated sugar and butter in a bowl. Mix with your hands until well combined. Press 2 tablespoons of the mixture into the cupcake liners and bake for 7 minutes. Remove and let cool.
For the chocolate cake: Preheat the oven to 325 degrees F. In the bowl of an electric mixer with the whisk attachment, whisk the flour, cocoa powder, granulated sugar, baking soda, baking powder and salt until well combined. Add the eggs, one at a time, scraping the bowl as needed. Add the buttermilk, vegetable oil, vanilla and coffee and mix for about a minute until well combined. Fill the 36 muffin pans with the pre-baked graham cracker crust three-quarters full with batter and bake until a toothpick inserted comes out clean, about 20 minutes.
For the peanut butter cream cheese filling: Whip the cream cheese and butter in an electric mixer with the paddle attachment until fully incorporated. With the mixer on low, gradually add the powdered sugar until combined. Add the vanilla and mix until combined. Finally, add the peanut butter and mix until fully incorporated.
For the marshmallow frosting: In small saucepan, combine the granulated sugar, 5 ounces water and the cream of tarter and boil until the sugar dissolves, stirring occasionally.
In the bowl of an electric mixer with the whisk attachment, beat the egg whites and vanilla until firm peaks form. With mixer on high, slowly stream the hot sugar mixture into the egg whites and mix for about 3 minutes.
To assemble: Use a knife to cut a hole out of the center of the cupcakes. Fill with peanut butter cream cheese filling with a spoon and frost with marshmallow frosting.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.