Preheat oven to 350 F. Line cookie sheets with parchment paper; set aside. In a large bowl, combine the cake mix, Cool Whip, and egg. Stir well until a sticky dough forms; this will take a few minutes of stirring. Cover with plastic wrap and chill in fridge for 30 min - 1 hour to stiffen up a bit - optional step.
Pour the powdered sugar out onto a plate. Use a cookie scoop or melon baller to create 1-inch balls of dough and drop them on to the plate of powdered sugar a few at a time.
Roll the balls in the powdered sugar then place them on the prepared cookie sheets, leaving at least 1 ½ inches of space between each cookie dough balls.
Bake at 350 F for 8-10 minutes until cracking on the edges and middle is no longer wet. I like a really chewy outcome so 8 minutes is best for us because as they cool they will stiffen up a bit but still maintain a really really soft consistency in the center. For stiffer bake for 10 min.
Cool the cookies on the cookie sheets to stiffen up, enjoy once cooled.