Those Two-Tone Confetti Cupcakes

Last month, I made Cinnamon Two-Tone Cupcakes with 1/2 box of yellow cake mix, using Wilton two-tone cake inserts. I observed that the interior columns of the cakes were blobby. This time, for the other half box, instead of a cinnamon and nutmeg mix for the interior part, I used 3 tablespoons of rainbow jimmies. Read the entire article and comment there, please.