Bring a large pot of salted water to a rolling boil and cook the rigatoni according to package instructions until al dente.

While the water heats, add olive oil to a large skillet or Dutch oven over medium-high heat.

Add the crumbled sausage meat to the skillet and cook for 5-7 minutes, breaking it apart with a wooden spoon until browned and cooked through.

Reduce the heat to medium, add the chopped onion, minced garlic, and fennel seeds, and sauté for 3-4 minutes until the onions are softened and fragrant.

Pour in the crushed tomatoes, season with a pinch of salt and pepper, and bring the sauce to a gentle simmer for 10 minutes to meld the flavors.

Lower the heat to low and stir in the heavy cream, simmering for another 2 minutes until the sauce is a rich, creamy pink color.

Drain the pasta, reserving about 1/2 cup of the pasta cooking water just in case the sauce needs thinning.

Toss the cooked rigatoni directly into the sauce, adding the grated Parmesan cheese, and stir until the pasta is evenly coated.

Serve immediately in warm bowls, garnished with fresh basil leaves and extra Parmesan cheese if desired.