Heat oven to 350 degrees F. In medium bowl, break apart cookie dough. Knead in baking cocoa until thoroughly combined.
Shape dough into 20 (1 1/2-inch) balls. Place on ungreased cookie sheets, and press down slightly with fingers. Bake 10 to 13 minutes or until centers of cookies are set; cool 2 minutes on pans. Transfer to cooling racks to cool completely, about 15 minutes.
Meanwhile, with spatula sprayed with cooking spray, transfer marshmallow creme to microwavable cup sprayed with cooking spray. Microwave uncovered on Medium (50%) 60 to 90 seconds or until melted. Cool slightly, then transfer to resealable food-storage plastic bag.
Cut 1/8 inch from 1 corner of bag, then drizzle cookies with marshmallow creme, and sprinkle with crushed peppermint candies. Refrigerate at least 30 minutes but no longer than 12 hours before serving.