Place the cake mix, eggs and thawed whipped topping in large bowl. Blend for 1 to 2 min. with mixer on med. speed or with wooden spoon until well blended and all dry ingredients are moisten(dough will be stiff) Refrigerate dough, covered for 30 min. Preheat oven to 350. Position oven rack in middle of oven, set aside ungreased cookie sheets. Place powdered sugar in a small shallow dish. Shape dough into 1 inch balls. Roll cookies in powdered sugar to coat. Place 2 inches apart on ungreased cookie sheets. Bake for 10 to 12 min. or until cookies are puffed in appearance and firm at edges(centers will be slightly soft). Let cookies rest on cookie sheets for 2 min.(cookies will fall, giving them a cracked apperance). Transfer cookies to wire rack with metal spatula, and cool completely.