Preheat oven to 350°F. Line baking sheets with parchment paper or Silpat. Set aside.
In a large bowl, combine the cake mix, egg and thawed whipped topping. (Note: The batter will be thick and sticky.).
Using a tablespoon measure, form the dough into balls and roll in powdered sugar. Place 2-inches apart on the prepared pan.
Bake for 8-12 minutes or until the edges are golden brown. Allow to cool on the pan for 3 minutes before transferring the cookies to a wire rack to cool completely.