1. Cook the Rigatoni: Bring a large pot of salted water to a boil. Cook the rigatoni according to package instructions until al dente. Reserve 1/2 cup of pasta water, then drain and set aside.

2. Brown the Sausage: In a large skillet over medium heat, cook the sausage, breaking it into crumbles, until browned and cooked through. If the sausage releases a lot of fat, drain some of it, leaving about a tablespoon for flavor.

3. Sauté Aromatics: Add chopped onion to the skillet and cook until softened, about 3-4 minutes. Stir in minced garlic and red pepper flakes (if using), cooking for another minute until fragrant.

4. Deglaze the Pan: Pour in the white wine (or chicken broth) to deglaze the pan, scraping up any flavorful bits from the bottom. Let it simmer until the liquid reduces by half, about 2-3 minutes.

5. Make the Creamy Sauce: Stir in the crushed tomatoes, Italian seasoning, and a pinch of salt and pepper. Simmer for 5 minutes, allowing the flavors to meld. Reduce heat to low, then add the heavy cream, Parmesan, and mozzarella, stirring until the cheese melts into a creamy sauce.

6. Combine with Pasta: Add the cooked rigatoni to the skillet, tossing gently to coat the pasta in the creamy sausage sauce. If the sauce is too thick, add a splash of the reserved pasta water to reach your desired consistency.

7. Garnish & Serve: Remove from heat and garnish with fresh basil or parsley. Serve hot with extra Parmesan on the side.