Start by bringing a large pot of salted water to a rolling boil. Add your rigatoni and cook for 8-10 minutes, or until al dente, then reserve 1 cup of pasta water and drain.

In a large skillet, heat a tablespoon of olive oil over medium heat. Add the diced onion and sauté for 4-5 minutes until it becomes translucent.

Add minced garlic to the skillet and cook for about 1 minute, stirring continuously until fragrant.

Crumble the Italian sausage into the skillet, cooking and stirring for 6-8 minutes until browned and no longer pink.

Stir in the canned tomatoes with their juices, let it simmer over medium heat for about 15 minutes.

Season the sauce with red chili flakes, salt, and pepper to taste.

Reduce the heat to low and stir in the heavy cream, simmer for another 5-7 minutes until thickened.

Gradually stir in the grated Parmesan cheese until fully melted and creamy.

Add the drained rigatoni to the skillet, tossing gently to coat each piece evenly in the sauce.

Serve the creamy rigatoni warm, garnished with additional grated Parmesan and fresh basil.