Preheat Your Oven. Start by preheating your oven to 350°F and lining a baking sheet with parchment paper or a silicone baking mat.
Mix Ingredients. In a large mixing bowl, combine the cake mix, Cool Whip, and egg. Stir until well combined and a soft dough forms.
Form Cookies. Using a spoon or cookie scoop, portion the dough into small balls and place them on the prepared baking sheet, leaving space between each cookie.
Roll in Powdered Sugar. Roll each dough ball in powdered sugar to coat evenly for a sweeter finish.
Bake. Bake the cookies in the preheated oven for 10-12 minutes, or until the edges are set and the tops are lightly golden.
Cool and Enjoy. Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely. Enjoy your fluffy, delicious Cool Whip Cookies!