Death-by-Butter Cookies

Ingredients:
1 box Duncan Hines butter recipe cake mix,
1 stick butter,
1/4 tsp vanilla extract,
1 pkg cream cheese @ room temperature (8 oz. pkg),
1 egg
Directions:
Combine all ingredients with electric mixer until well blended.
Chill dough for two hours.
Roll into balls (about walnut size).
Roll balls in powdered sugar.
Bake on ungreased cookie sheet in 350 degree oven for 10-12 minutes.
Dust with powdered sugar when completely cooled.
These are also called:
Gooey Butter Cookies