Preheat the oven to 185 degrees. Slice rolls in half and lay them, cut side up, on a large baking sheet.
Top each half with a generous portion of either salsa sauce or pesto. Next, top with a generous amount of grated mozzarella and Parmesan, if you’d like. Add whatever toppings you’d like on top of the cheese!
Once all assembled, put the pan in the oven on the lowest rack for 8 to 10 minutes. Crank up the heat to 210 and put it on the highest rack until the cheese starts to bubble a bit and turn golden.
Remove and serve immediately!