To a medium pot of boiling water on the stove add in the box of macaroni (save the cheese packet for later) and boil for 7 minutes or until the pasta is tender. Drain and set to the side.
To a large skillet over medium heat add the diced pepper, onion and sausage break the sausage up and cook it through. Remove any grease in the pan then add in the cooked macaroni noodles, cheese packet and pizza sauce stir well. Spray a 9 x 13 baking dish with nonstick spray then add this casserole mixture in there. Top with the pepperonis and mozzarella cheese. Bake for 30 to 35 minutes. Enjoy!