Preheat oven to 350 degree F. Line cookie sheets with parchment paper; set aside. Slice each dough piece in half and shape each piece into a ball (should have 48 balls). Place 2 inches apart on prepared cookie sheets. Bake for 8 minutes. Push a marshmallow half, cut side down, into each cookie; bake 1 minute more. Remove and cool on wire racks.
Frost with Chocolate Frosting and sprinkle with crushed candies. Makes 48 cookies.
In a very large mixing bowl, beat butter, softened, and unsweetened cocoa powder with an electric mixer on medium speed until smooth. Gradually beat in 2 cups powdered sugar until well combined. Gradually beat in milk and vanilla until well combined. Gradually beat in 6 cups powdered sugar. If necessary, beat in additional milk, 1 teaspoon at a time, to reach spreading consistency.