In a large bowl stir together cookie dough, flour, cocoa powder, and red food coloring until combined (knead dough with hands, if necessary to combine, use food handling gloves to prevent your hands from staining).

Shape dough into a 7-inch roll. Wrap in plastic wrap and freeze for 2 to 3 hours or until dough is firm enough to slice.

Preheat oven to 375 degrees F.

Cut roll into 1/4-inch slices. (If the dough crumbles slightly when you slice it, press dough together to re-shape the slice into a round.)

Place slices 2 inches apart on a parchment-lined cookie sheet. Bake about 7 minutes or until edges are firm.

Transfer cookies to a wire rack; cool.

Place frosting in a small microwave-safe bowl. Microwave on high for 10 to 20 seconds or just until melted; stir.

Dip half of each cookie into melted frosting, allowing excess frosting to drip back into bowl. Repeat dipping if necessary for a thicker coating.

Return cookie to wire rack. Sprinkle dipped portions of cookies with chocolate sprinkles. Let stand until frosting is set.

To Store: Layer decorated cookies between sheets of waxed paper in an airtight container; cover. Store in the refrigerator for up to 3 days or freeze for up to 3 months.