In a large bowl, add the cake mix, Cool Whip, and egg. Beat with a mixer until smooth and combined. Cover and refrigerate for 30 minutes.

Place powdered sugar in a bowl. Using a cookie scoop, drop the chilled dough into the powdered sugar. Roll into a ball and place on a greased baking sheet about 2 inches apart.

Bake at 350°F for 12 minutes or until the bottoms are golden brown. Let cookies cool on the sheet for 5 minutes before transferring to a wire rack.