This is one of my moms version of baked penne. I have changed it some just to add a veggie after tasting one very similar at my local store. Now its a staple in the dish at my house. She also has started to add in some spinach.
Prepare pasta as directed on package until al dente, about 8 minutes. Drain and return to the pan.
While pasta is cooking, heat large skillet, add sausage, onion, and garlic. Saute' until sausage is cooked through. Drain off any grease. Add mushrooms and saute' 3 minutes. Add pepper, italian seasoning and tomatoes to pan. Simmer, stirring occassionally, about 8 minutes.
Combine sausage mixture to pasta, spinach, mozzarella cheese and 1/3 cup of parmesan cheese.
Pour into 13x9 glass baking dish. Top casserole with remaining 2/3 cup parmesan cheese.
Bake uncovered 15 minutes or until cheese is melted and sauce is bubbling.