Add oil to heavy bottomed pan for sauce. Break tomatoes up with hands. Discard the small ends that don't break up. It's important here to use a high quality brand that specifically says San Marzano, so you don't end up with a lot of pulp.
Cook on medium for thirty minutes.
Use a blender or immersion blender to make the sauce smooth.
If using Italian sausage, fork, and bake for twenty minutes at 400 degrees.
Add meatballs and sausage into sauce, while pasta is cooking.
Cook pasta according to directions.
Drain pasta, arrange in baking dish, with sliced meatballs and or sliced sausage, ricotta cheese. Sprinkle with parmesan or pecorino romano. Top with mozzarella.
Bake at 375 degrees F. until cheese is completely melted, about twenty minutes.