Preheat oven to 350°F and mist a large baking sheet with non-stick spray.
Combine cake mix, Cool Whip, and egg until fully blended.
Use a medium cookie scoop to form 1 tbsp-sized dough balls and roll in powdered sugar.
Arrange on baking sheet and bake 12–15 minutes until puffed and slightly golden.
Let cookies rest 5 minutes on the sheet before transferring to a rack.
