Ingredients For the Cookies: 1 cup unsalted butter 1 cup granulated sugar 3/4 cup packed brown sugar 2 eggs 1 teaspoon vanilla 1/2 teaspoon salt 1 1/4 cups unsweetened cocoa powder 1 3/4 cups all-purpose flour 1 teaspoon baking powder 1 teaspoon baking soda For the Filling: 1 cup (2 sticks) unsalted butter, softened 2 tablespoons brown sugar 2 1/2 cups flour 1 13 oz container marshmallow creme 1 teaspoon vanilla 1/2 teaspoon salt 1/3 cup mini chocolate chips For the Cookies: Heat oven to 350 degrees. In a large bowl, cream together the butter, brown sugar and white sugar until light and fluffy. Add the vanilla extract and then the eggs one at a time, beating well with each addition. Combine the salt, cocoa, flour, baking powder and baking soda and gradually stir into the creamed mixture. Shape dough into 1 1/2 T sized balls and place on a baking sheet. Flatten cookies slightly with the bottom of a drinking glass or your palm. Bake 8-10 minutes or until the cookies are puffy and the tops are cracked, but still soft. Allow cookies to cool on baking sheet for 5 minutes before removing to a wire rack to cool completely. For the Filling: With an electric mixer, cream butter until fluffy. Add sugar and beat well. Add flour and beat until all the flour is incorporated. Add remaining ingredients and beat until mixture is smooth. (It will be fairly thick). Assembling the Sandwiches: Scoop about 3T of filling onto to bottom of a cooled cookie. Top with another cookie and eat. Yield: 15 large sandwiches