S'mores Cupcakes

Cupcakes:
1 1/2 cups flour
3/4 cup unsweetened cocoa powder
1 cup sugar
1/2 cup brown sugar (lightly packed)
1 teaspoon baking soda
1 teaspoon baking powder
2 eggs
3/4 cup buttermilk
3 tablespoons oil
1 teaspoon vanilla
3/4 cup warm water

Frosting:
1 - 1 1/2 cups graham cracker crumbs
3/4 cup butter
4 ounces cream cheese
2-3 cups powdered sugar
1 teaspoon vanilla

Filling:
1 mini marshmallow or 1/4 large marshmallow

Bake at 350 degrees for 18-20 minutes

Adapted From:
http://www.marthastewart.com/282243/one-bowl-chocolate-cupcakes
http://www.cupcakeproject.com/2011/05/key-lime-pie-cupcakes-upside-down-key.html