graham cracker crumbs, sugar, melted butter, and cinnamon until well blended.
Divide evenly and press crumbs into each muffin wrapper.
In a small saucepan, melt butter over low heat. Add the unsweetened chocolate squares and continue to melt until well combined. Let this mixture cool.
Mix the flour, baking soda, and salt. Add these dry ingredients to the chocolate mixture and blend well. Mix the vinegar and milk into the chocolate batter.
Ladle ½ cake batter into each muffin wrapper. Place 1 t. of marshmallow cream into the center of each cupcake. Then top with the remaining cake batter making sure the tops are covered. Bake 20 minutes. When cool, top with whipped topping