Preheat oven to 400. Lightly grease a large casserole dish or two smaller casserole dishes with cooking spray.
Cook penne noodles according to package instructions. Drain and place in a large bowl. Add alfredo sauce, oregano, basil, garlic powder, salt and pepper, and 2 tablespoons parmesan cheese. Mix well to combine. (*Optional: add chicken and peppers here.) Scoop mixture into casserole dish and sprinkle with remaining parmesan cheese. Bake 20 minutes and serve hot.
***Optional: If you would like to include the mushrooms (which I highly recommend!) saute the mushrooms over medium high heat with oil and garlic about 5 minutes or until fragrant and mushrooms are slightly browned on each side. Add before scooping into casserole dish.