Preheat oven to 350°F.
With a hand mixer, beat butter, egg, and cream cheese until fluffy. Add in cake mix and beat until smooth.
Chill in the refrigerator for 30 minutes.
Add ½ cup powdered sugar to a small bowl. Use a medium cookie scoop to scoop out dough and roll it into balls. Dip in powdered sugar. Place on a greased cookie sheet and lightly press the tops to flatten them a bit.
Bake for 12-13 minutes. After removing from the oven, sift the tops of the cookies with powdered sugar if desired.