Fill a large pot with salted water and bring it to a rolling boil. Add the rigatoni and cook for about 8-10 minutes until al dente, stirring occasionally.

Reserve 1 cup of the pasta water, then drain the rigatoni in a colander. Set it aside while you prepare the sauce.

Heat olive oil in a large skillet over medium heat. Add the diced onion and cook for about 4-5 minutes until it’s translucent, stirring frequently.

Stir in the minced garlic and sauté for another minute until fragrant, making sure not to let it burn.

Crumble the Italian sausage into the skillet, cooking it until browned, about 6-8 minutes. Stir occasionally to break it up and cook evenly.

Pour in the canned tomatoes, breaking them up with a spoon. Let the mixture simmer for about 15 minutes, stirring occasionally to blend flavors.

Add red chili flakes, salt, and pepper to taste. Mix well and adjust the seasoning for your preference.

Lower the heat slightly and gradually pour in the heavy cream while stirring continuously. Allow it to simmer gently for an additional 5-7 minutes to thicken.

Stir in the grated Parmesan cheese until it melts and integrates fully into the sauce. If it's too thick, use your reserved pasta water to reach your desired consistency.

Add the cooked rigatoni to the skillet, tossing it gently to coat the pasta with the creamy sauce. Ensure all the noodles are well covered.

Plate the creamy pasta and sprinkle more Parmesan on top. Finish with fresh basil for a pop of color and aromatic flavor.