Preheat the oven to 350°F and line a baking sheet with parchment paper.
In a large mixing bowl, use an electric mixer on low to combine 15.25 oz box white cake mix, 8 ounce Cool Whip, thawed, and 1 egg together. Mix until well combined.
Divide the mixture evenly into two small bowls. Add red food coloring to the batter in one bowl, and blue food coloring to the second bowl.
Pour ½ cup confectioners sugar into a shallow bowl. Use a 1 tablespoon cookie scoop to drop dough balls directly into the confectioners' sugar, then roll to coat.
Place the sugar-coated cookie dough balls on the prepared baking sheet and bake for 10 minutes in the preheated oven. If using sprinkles, add Red, white, and blue sprinkles to the tops of cookies after about 6 minutes of cooking.
Remove from the oven and transfer to a wire rack to cool.
Notes
Add sprinkles around the 6-minute cooking mark. Move quickly. At this point in the baking process, the cookie will expand, exposing cake batter so the sprinkles will stick.
To make perfectly shaped cookies, use a glass and swirl around each cookie when it’s still hot from the oven.
These cookie dough balls are sticky! Drop straight into the powdered sugar, do not try to roll in your hands.