You can use canned biscuits or rolls for the crust and then create a filling or you can use non-stick spray and do mini-omelets. Some can be baked ahead of time and then frozen for later use on those busy summer days!
You are limited only by your imagination and your family's preferences!
The links below are to a Pillsbury website and Coleen's Recipes blog. Both have recipes using muffin pans.
https://www.pillsbury.com/everyday-eats/dinner-tonight/times-our-muffin-pan-made-us-dinner
http://coleensrecipes.blogspot.com/2012/02/easy-baked-mini-omelets.html