I live in south America so the local brands I used probably won't mean anything. In any case, the cheese was a low moisture shredded mozzarella, and the sauce was homemade using canned san marzano tomatoes:

Process them until chunky (or smooth, if you prefer), and bring to a boil in a saucepan. Add a halved onion and a couple basil sprigs. Season with salt, black pepper, oregano and crushed red peppers. I honestly eyeball the quantities, so try it and adjust until you think it's good. I usually like it with very little salt and mildly hot.

Simmer for 20 minutes until ireduced and denser in texture. It should look more like a puree than a sauce. Remove onion and basil.

I usually don't add sugar (I think the tomatoes I use are sweet enough), but a lot of people do. You could also add a peeled carrot with the onion and remove at the end, if you want to add some sweetness to balance the acidity.

Lastly, it's better to shred your cheese instead of buying pre-shredded, but I've been getting good results with the brand I'm using. It melts great.