Gooey Butter Cookies

1 box Butter Recipe Cake Mix

1 stick butter, softened

1/4 teaspoon vanilla extract

1 package cream cheese, softened

1 egg

Combine all ingredients with electric mixer until well blended.  Chill dough for 2 hours or over-night.  Roll into balls (about walnut size).  Roll balls in powdered sugar.  Bake on ungreased cookie sheet in 350˚oven for 10-12 minutes. 

Dust with powdered sugar when completely cooled.