In a 5 quart pot, stir together spaghetti sauce, beef broth, basil, oregano, garlic, bay leaf and crushed red pepper. Add fully cooked meatballs. Bring to a boil over medium-high heat, stirring occasionally. Turn heat down to low, cover and simmer for at least 20 minutes. *If using frozen meatballs, increase the time as needed.
In the meantime, cook pasta according to package directions. Drain and set aside. If using spaghetti, cut into bite-sized pieces (optional).
To serve, add about a some pasta to each bowl and ladle soup over. Top with freshly grated Parmesan cheese and chopped parsley.