Fill a large pot with water and add a pinch of salt. Bring it to a rolling boil and add the rigatoni, cooking until al dente, about 8-10 minutes. Reserve about a cup of pasta water before draining.

In a large skillet over medium heat, heat a tablespoon of olive oil. Add diced yellow onion and sauté for 4-5 minutes until translucent.

Add minced garlic and sauté for an additional minute until fragrant. Be careful not to brown the garlic.

Add Italian sausage to the skillet, breaking it up while cooking. Sauté for 6-8 minutes until browned and cooked through.

Pour in the canned tomatoes, breaking them up as you mix them with the sausage. Allow to simmer for 15 minutes on low heat.

Stir in red chili flakes, salt, and pepper to taste, adjusting as necessary for flavor balance.

Lower the heat and pour in the heavy cream, stirring to combine. Let it simmer for 5-7 minutes until thickened.

Sprinkle freshly grated Parmesan cheese into the sauce, stirring until melted. Add reserved pasta water if the sauce is too thick.

Add the drained rigatoni to the skillet and toss it in the creamy sauce until fully coated.

Plate the rigatoni and finish with an extra sprinkle of Parmesan cheese and fresh basil leaves as garnish.