Spaghetti with Meatballs

Name: Spaghetti with Meatballs
Ingredients: 1/4 cup milk; 2 slice white bread, cut into cubes; 1 pound 80 percent lean ground beef; 1/2 medium onion, diced; 1 egg; 1 tablespoon chopped garlic; 1 tablespoon Italian seasoning; 1/2 teaspoon salt; 1/4 teaspoon ground black pepper; 2 sticks mozzarella string cheese, cut into small cubes or 1/2 cup shredded mozzarella; Nonstick cooking spray; 2 tablespoons olive oil; 1/2 medium onion diced; 1 (28-ounce) can diced tomatoes; 2 tablespoons freshly chopped basil leaves; 2 tablespoons freshly chopped parsley leaves; Salt and freshly ground black pepper; 1 (16-ounce) box spaghetti