Bring a large pot of well-salted water to a rolling boil. Cook the pasta according to package directions, one minute less than suggested. Drain and do not rinse.

In a large skillet, heat olive oil over medium-high heat. Add sliced sausage and sear for 2 to 3 minutes per side until caramelized. Transfer to a plate, leaving the fat in the pan.

In the same skillet, reduce heat to medium and add diced onion and red bell pepper. Cook for 4 to 5 minutes until softened, then add minced garlic and cook for 1 minute.

Sprinkle Cajun seasoning over vegetables and toast in the pan for 30 seconds.

Add chicken broth, scraping up the browned bits from the bottom of the pan. Pour in cream and bring to a gentle simmer for 3 to 4 minutes until slightly thickened.

Reduce heat to low and add grated Parmesan, stirring constantly until melted and smooth.

Return the sausage to the skillet and add drained pasta. Toss gently to coat, adding reserved pasta water if the sauce is too thick. Cook on low for another 1 to 2 minutes.

Serve immediately, garnished with chopped parsley and extra Parmesan if desired.