01 -
Preheat oven to 350°F and lightly spray a 2-quart baking dish. Cook pasta according to package directions; rinse and drain.
02 -
In a heavy skillet, brown Italian sausage, chopped onion, sliced mushrooms, and minced garlic over medium heat. Drain excess fat.
03 -
In a large bowl, blend pasta sauce, cream, oregano, and 2 tablespoons of grated Parmesan or Romano cheese until smooth.
04 -
Incorporate the browned sausage mixture, halved pepperoni, and sliced olives into the sauce. Stir to combine thoroughly.
05 -
Transfer mixture into the prepared baking dish, cover with foil, and bake for 30 to 35 minutes.
06 -
Remove foil and evenly top casserole with shredded mozzarella and the remaining 2 tablespoons of Parmesan or Romano cheese. Return to oven and bake 10 to 15 minutes until cheese melts and begins to brown.