Spread an even layer of frosting over the tops of the cupcakes. Pour a generous amount of the orange sprinkles into a small bowl. Dip the freshly frosted cupcake into the sprinkles and move it around to make sure all of the top is evenly coated in sprinkles, so that there is no more white frosting showing.
Place the cookie in the middle of the top of the cupcake (you'll want to smear some frosting on it, to help it stick). Using your black decorating gel, draw a mouth on top of the cookie. Next to the cookie, on top of the orange sprinkles, draw horizontal lines with the black gel to the edge of the cupcake.