In a large bowl, beat cream cheese and butter with a mixer at medium speed until smooth. Reduce mixer speed to low; gradually add confectioners’ sugar, sour cream, sprinkles, and vanilla. Beat until smooth.
Note: Do not use nonpareil sprinkles. The colors will bleed.
Recipe by The Ribbon in My Journal - Phyllis Hoffman DePiano at https://www.theribboninmyjournal.com/big-sisters-birthday-a-sisters-tale/