1Cook pasta according to "al dente" directions on the box; drain and set aside.
2Saute onion, pepper, and garlic in olive oil until onions are translucent; set aside.
3In same pan, brown sausage until no longer pink; drain fat. Add 1-2 jars of sauce, depending on how "saucy" you like it.
4In a large bowl, combine pasta, onion mixture, and sausage mixture with 2 cups shredded mozzarella cheese. Pour mixture into a 9x13 pan coated with cooking spray. Sprinkle with remaining 1 cup cheese.
5Bake at 375 degrees for about 45 minutes or until bubbly on the sides.