Begin by bringing a large pot of salted water to a boil. Add the rigatoni and cook until al dente, about 10-12 minutes. Drain and keep warm.

In a large skillet, heat olive oil over medium heat. Add the crumbled sausage and cook for 5-7 minutes until browned.

Add the diced onion to the skillet and sauté for 3-4 minutes until translucent. Stir in the minced garlic and cook for 1 minute.

Pour in the crushed tomatoes, heavy cream, and chicken broth, then stir in the Italian seasoning and red pepper flakes. Simmer for 10 minutes.

Add the drained rigatoni to the skillet and toss to coat. If the sauce is too thick, add reserved pasta water as needed.

Sprinkle the grated Parmesan cheese over the pasta, stirring until melted and creamy.

Serve warm, garnished with fresh basil leaves.