Preheat oven to 350 degrees F. Add cupcake liners to a pan and set aside.

Add graham crackers to a blender or food processor and mix until fine crumbs are formed. 

In a small bowl add crumbs, melted butter and sugar. Mix until crumbs have been coated in the butter and a wet but sticky texture is achieved. 

Put 1 Tbsp of cracker mixture in each cupcake liner. Use a spoon to firmly press down the crumbs into a flat surface. (I used the top of a sprinkles lid and it worked great). Bake for 7 minutes and remove from the oven.

Meanwhile add all cupcake ingredients into a large bowl and mix on medium speed for 2 minutes. Add 2 Tbsp of batter into each cupcake liner. Bake for 17 minutes or until a toothpick inserted in the middle comes out clean. 

Allow cupcakes to rest in the pan for 5 minutes then transfer to a cooling rack to come to room temp. 

To make the frosting, cream the butter for 1-2 minutes on medium speed until it is light and fluffy. Add 1 jar of marshmallow cream and mix to combine. On a slower speed, add 1.5 cups of powdered sugar. Mix until combined. 

Incorporate the remaining jar of marshmallow cream followed by another 1.5 cups of powdered sugar. Continue to mix on high until a smooth, glossy frosting has formed.