Julie's Spaghetti alla Margherita

1 pound spaghetti, cooked "al dente," drained
1/4 c olive oil
2 T butter
2 large cloves garlic, slivered
10 large Roma tomatoes (about 2 pounds), coarsely chopped (or two cans of diced tomatoes)
1 t sugar
1 t kosher salt
1/2 t freshly ground black pepper
1 c fresh basil leaves, coarsely chopped
1/2 pound fresh mozzarella cheese, cut into 1/2-inch cubes
1/2 c freshly grated Roman cheese (Jules used parmesan)

Cook spaghetti to al dente while making the sauce.  Do not overcook!
In large skillet, heat olive oil and butter over low heat.  Add the slivered garlic and cook for 30 seconds until fragrant.
Add the chopped tomatoes, sugar, salt and pepper.  Cover; simmer for 10 minutes.
Turn off the heat. Add the chopped fresh basil and the cooked spaghetti.  Cover and heat for about 2 minutes to warm the pasta thoroughly.
Place the steaming hot past and sauce in a large serving bowl, toss in the fresh mozzarella and grated cheese.  Stir well and serve at once.

Serve with Julie's Focaccia Bread