Brown the sausage in a large skillet over medium-high heat for 3-5 minutes, breaking it into chunks. Transfer to a plate, leaving drippings in the skillet.

Sauté sliced onion and bell peppers in the skillet for 3-5 minutes until softened, then cook an additional 15-30 minutes until tender and golden brown.

Add grape tomatoes to the skillet and cook for 5 minutes until tomatoes soften and release their juices.

Return the sausage to the skillet with chopped pepperoni and cook for another 2-3 minutes until pepperoni crisps.

Add cooked rigatoni, mozzarella, Parmesan, and spaghetti sauce, stirring for 3-5 minutes until cheese melts and mixture is warmed through.

If the skillet is oven-safe, preheat the broiler, top with sliced mozzarella, and broil for 1-2 minutes until melted and golden.

Remove from oven, sprinkle crispy pepperoni, Italian seasoning, and fresh basil, stirring gently before serving.