In a medium mixing bowl, combine the softened cream cheese, powdered sugar and cake mix with an electric mixer.Mix well for a few minutes until it begins to whip. Careful with this stuff. Anyone that makes frosting can tell you that the more you whip cream cheese and powdered sugar, the more you end up with…lol.Once you’ve got a good whip happening, add in the vanilla and melted butter.Whip it. Whip it good! (yes, I did go there…had to be done. )Make sure your vanilla and butter is combined well and chill.Chill for at least 2 hours before serving.Top with sprinkles in the colors of your choice (we use rainbow sprinkles! Yay!) before serving and enjoy!