To stack cookies, wait until frosting dries, then place waxed paper in between the layers to keep the frosting from smearing.
- 1 3/4 cups all-purpose flour
- 3/4 cup cocoa powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon salt
- 1/2 cup (1 stick) unsalted butter, softened
- 1 cup sugar
- 1 large egg
- 1/2 cup milk
- 1 teaspoon pure vanilla extract
- 12 large marshmallows, cut in half horizontally
- Chocolate Frosting for Surprise Cookies
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.