Food & Cooking Recipes Dessert & Treats Recipes Cookie Recipes Surprise Cookies 3.6 (288) Close Prep Time: 25 mins Total Time: 35 mins Yield: 2 dozen These delicious treats were inspired by mugs of hot chocolate topped with marshmallows. Directions Preheat oven to 375 degrees. In a medium bowl, whisk together flour, cocoa powder, baking soda, and salt; set aside. In the bowl of an electric mixer fitted with the paddle attachment, cream together butter and sugar until light and fluffy, about 2 minutes. Add egg, milk, and vanilla, and beat until well combined. Add reserved flour mixture; mix on low speed until combined. Using a tablespoon or 1 3/4-inch ice cream scoop, drop dough onto ungreased baking sheets, about 2 inches apart. Bake until cookies begin to spread and become firm, 10 to 12 minutes. Remove baking sheets from oven, and place a marshmallow, cut-side down, in the center of each cookie, pressing down slightly. Return to oven, and continue baking until marshmallows begin to melt, 2 to 2 1/2 minutes. Transfer cookies to a wire rack to cool completely before frosting. Spread about 1 tablespoon of frosting over each marshmallow, starting in the center and continuing outward until marshmallow is covered. Cook's Notes If you're putting two sheets in the oven at a time, switch top and bottom sheets halfway through for more even baking. To stack cookies, wait until frosting dries, then place waxed paper in between the layers to keep the frosting from smearing.