In a medium bowl, cream together cream cheese and butter.
Mix in the egg and vanilla.
Add cake mix and mix until well blended.
Hand stir in colored sprinkles.
Use a cookie scoop (or roll dough into 1" balls). Roll each cookie dough ball in powdered sugar and place on lined cookie sheet (I use a silicone liner), but parchment is fine.
Baked in preheated 350* oven for 10-13 minutes, or until bottoms of cookies are light golden brown. Cool on wire racks.