Bring a large pot of salted water to a rolling boil over high heat. Add the rigatoni and cook until al dente, about 10-12 minutes, stirring occasionally. Once cooked, drain the pasta and reserve a cup of the pasta water. Keep warm while preparing the sauce.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the Italian sausage, breaking it apart as it cooks. Sauté for about 5-7 minutes until browned.

Once the sausage is browned, add the chopped onion and sauté for 3-4 minutes until translucent. Stir in the minced garlic and red pepper flakes, cooking for an additional minute.

Pour in the crushed tomatoes and stir to combine. Bring to a gentle simmer and let bubble for about 10 minutes.

Reduce heat to low and stir in the heavy cream. Simmer for an additional 5 minutes while stirring occasionally.

Carefully add the warm rigatoni to the creamy sauce, tossing gently to coat each piece. Add reserved pasta water for desired consistency.

Sprinkle the freshly grated Parmesan cheese over the pasta and stir until melted and well incorporated.

Garnish with fresh basil leaves and serve immediately while hot.