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. Fold in white chocolate chips, if desired.
Chill in the refrigerator for 30 minutes.
If using powdered sugar, 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. If using white chocolate chips, top with a few white chocolate chips when the cookies come out fresh from the oven. If using powdered sugar, after the cookies are removed from the oven, sift the tops of the cookies with powdered sugar.