If desired, peel tomatoes; remove seeds, straining juice into a bowl.
Save the juice and discard seeds. In a food processor, combine garlic, tomatoes with juice, 3 tablespoons olive oil, and basil. Pulse quickly to chop roughly.
Pulse more for a smoother sauce, if desired.
Transfer to a bowl, add salt and pepper and let stand to marinate for about 20 minutes.
Cook pasta until just tender, drain and toss hot with the marinated tomato sauce.
If hotter spaghetti is desired, heat the sauce just until hot on stove top or in microwave.
Serve immediately with Parmesan cheese.