While these are perfect as is if you want to add a little more flavor, why not try adding some pepperoni slices, onion, black olives, or green peppers. Or if you want to make them more like a calzone, try adding in some ricotta! There are so many possibilities, and the best part is that it's up to you what you add-in for your perfect pizza roll. Just be aware that adding in too many moisture-rich ingredients (like onions, mushrooms, etc.) may cause your dough to be soggy, so don't go too crazy.