In a large skillet over medium heat, cook the sausage and onion until the sausage is browned and the onion is tender, about 8-10 minutes. Break the sausage into small pieces as it cooks.
Add the minced garlic to the skillet and cook for an additional minute, until fragrant.
Stir in the crushed tomatoes and bring to a simmer. Reduce heat and let simmer for 10 minutes, allowing the flavors to meld.
Pour in the heavy cream and stir to combine. Season with salt and pepper to taste. Cook for another 2 minutes, until the sauce is heated through.
While the sauce is cooking, bring a large pot of salted water to a boil and cook the rigatoni according to package instructions, until al dente. Drain and set aside.
Add the cooked rigatoni to the sauce and toss to coat evenly.
Serve hot, garnished with chopped fresh basil and grated Parmesan cheese.