Bring a large pot of salted water to a boil. Add the rigatoni and cook according to package instructions until al dente, about 10-12 minutes. Drain and toss with olive oil.

In a skillet, heat 2 tablespoons of olive oil over medium heat. Add the Italian sausage and cook for 5-7 minutes until browned.

Add the chopped onion to the skillet and sauté for 3-4 minutes until soft and translucent.

Stir in the minced garlic and red pepper flakes, cooking for an additional minute until fragrant.

Pour in the crushed tomatoes and simmer for about 10 minutes until the sauce thickens slightly.

Lower the heat and stir in the heavy cream, simmer for another 5 minutes.

Add the cooked rigatoni to the skillet and toss to coat with the creamy sauce.

Sprinkle in the grated Parmesan cheese and stir until melted. Season with salt and pepper to taste.

Garnish with fresh basil leaves and serve immediately.