Use freshly grated parmesan rather than pre-shredded for the smoothest, creamiest sauce. Cook the sausage in batches to ensure a proper sear and caramelized crust. Always reserve pasta water before draining — it helps loosen the sauce and improve emulsification. Adjust the Cajun seasoning to your preferred heat level. Andouille sausage is a great substitute for a smokier, more traditional Cajun flavor.