Cook ziti in boiling, salted water following package; drain.
Heat olive oil in saucepan. Add ground beef and onion. Cook until meat is browned.
Pour off any excess fat.
Add garlic, tomatoes with can liquid, tomato sauce, oregano, and marjoram.
Preheat oven to 350° F.
Mix cooked ziti and sauce together in 2 1/2 qt. casserole dish.
Combine mozzarella and Parmesan cheeses; sprinkle over ziti mixture.
Sprinkle with chopped parsley and bake 25 minutes, or until lightly browned and bubbly.
Remove from oven, and serve.
Servings: 4