Preheat oven to 350 degrees.
Cook pasta in bowling water until al dente, about 6 minutes. Drain and put into a 9 x 13 casserole dish.
In a 6-quart pot heat 1 tablespoon of olive oil until hot and cook sausage until no longer pink. Break the sausage into small pieces as it cooks. Place the sausage on top of the pasta.
Using the same pot heat the other tablespoon of oil and cook the onions until translucent. Add in the mushrooms and cook until softened. Add in the garlic and cook for another 1 -2 minutes. Stir in the Italian seasoning, salt, and pepper and cook for another minute. Pour the vegetables in with the pasta and sausage.
Add the banana pepper slices and turkey pepperoni in with the other ingredients.
Next make the cheese sauce. Using the same pot, pour in the the chicken broth and milk. Whisk in the flour and bring to a slow simmer and then simmer for about 10 minutes. Continue to whisk so the flour doesn't stick to the bottom and burn.
Stir in the pizza sauce, granulated garlic, onion powder, and grated cheese. Continue to simmer until the sauce is hot.
Stir in the mozzarella cheese. When the cheese is melted pour the sauce over all of the ingredients in the 9 x 13 casserole dish. Stir all the ingredients together until everything is coated with the sauce.
Cover the casserole with foil and bake for 55 minutes. Remove the foil and bake for another 10 minutes.
Serve hot with a salad.