In a large bowl, combine the cake mix, sour cream, oil, sugar and eggs; beat on low speed for 30 seconds. Beat on medium for 2 minutes. Divide evenly among three bowls.
Stir one flavor of gelatin powder into each bowl until blended. Fill paper-lined muffin cups with a scant 2 tablespoons of each flavored batter.
Bake at 350° for 18-22 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes before removing from pans to wire racks to cool completely. Frost with cream cheese frosting. Decorate with sprinkles.