Combine butter, cream cheese, egg and vanilla in a bowl and use mixer until light and fluffy.

Stir in the dry cake mix until the dough becomes thick but smooth.

Pour powdered sugar into a separate bowl, set aside.

Scoop a spoonful of the cookie dough and roll into a ball, then dip in the powdered sugar until fully covered.  Tip - If you want easier dough to work with for rolling, chill in the refrigerator for 30 minutes

Place cookie balls on a baking sheet and bake at 350 degrees for 12 minutes.