Chocolate Fudge Cupcakes filled with Chocolate Fudge Cookie Bar and Marshmallow Meringue Frosting

Preheat the oven to 350 degrees F. Line cupcake pans with cupcake liners. Sift together the flour, sugar, cocoa, baking soda, baking powder, and salt. Set aside. In a large bowl, combine the buttermilk, oil, eggs, and vanilla. Slowly add the wet ingredients to the dry. Slowly stir in the coffee and water. Fill the cupcake pans about two-thirds full. Place a piece of Chocolate Fudge Cookie Bar in each cupcake. Bake until a toothpick inserted into the center of the cakes comes out clean, 9 to 11 minutes. Cool completely, and then frost with Marshmallow Meringue Frosting and enjoy! Preheat the oven to 350 degrees F. Combine the cookie crumbs and salt with the melted butter. Press into the bottom of a greased 13 by 9-inch pan. Bake for 8 minutes and let cool. Melt the chocolate chips and condensed milk together until completely melted and combined. Pour over the cookie crust and let cool. Beat the sugar, water, egg whites, and cream of tartar over a double boiler until stiff peaks form, 10 to 12 minutes. Remove from the heat and stir in the vanilla. Continue beating until the frosting is thick, about 3 minutes.