In bowl of food processor combine yogurt, olive oil, basil, garlic, parmesan cheese, pepper and salt. Process until all the ingredients are thoroughly mixed. Taste and adjust seasonings. Set aside.
Measure 1/2 of the sauce into large bowl and set aside. Bring large pot of water to boil. Season water with salt. Add pasta and cook until al dente (about 12 minutes). Drain. Add pasta gradually to the yogurt sauce. If added too quickly the sauce will break.
Garnish with basil leaves, chopped tomatoes and pine nuts if desired.