"Cheese and sprinkles" is a phrase that got popular after it was used in the film "Rio". It is NOT an idiomatic expression and doesn't mean absolutely anything. It's just something that some (very few) people from Minnesota like to say.

It is a phrase used in a movie called "Rio." It is not common and I'm not sure anyone knows what it means. It is supposed to be a regional expression used in Wisconsin and Minnesota, but I lived in Wisconsin for nine years and never heard it. Many Minnesotans are posting on Internet forums saying THEY have never heard it, either. Other say they have heard it and "it doesn't mean anything." I just watched this youtube clip https://www.youtube.com/watch?v=-Cnif5EhMR0 which is apparently where it is used.