In a large mixing bowl (I use my stand mixer), beat together the softened butter, Kahlúa Mocha, room temp egg and softened cream cheese until fluffy. Add the devil's food chocolate cake mix a little a time, fully incorporating each time. Chill the dough for 30 minutes in the refrigerator.
After 30 minutes, remove and preheat the oven to 350 degrees.
Roll the dough into balls. Roll each ball into your powdered sugar. Place on baking sheet about 2" apart or so.
Bake for 10-12 minutes.
Allow to cool for 2 minutes before moving to wire cooling rack to cool completely.