Cook the pasta in a large pot of salted water according to package directions. Reserve 1/2 cup of the pasta cooking water before draining.

Meanwhile, pat the shrimp dry with a paper towel and toss it with 2 teaspoons of the cajun seasoning.

Heat 1 tablespoon of olive oil in a large skillet or pan over medium heat. Add the sausage and shrimp and cook for about 4 to 6 minutes, until the shrimp are pink. Remove the sausage and shrimp from the pan and set aside.

Add the remaining tablespoon of olive oil to the pan, and once hot, add the diced onion and bell peppers. Sprinkle the remaining teaspoon of Cajun seasoning over the onions and peppers, and cook for 5 minutes, stirring occasionally.

Add the garlic to the pan and cook for 30 seconds, stirring continuously.

Pour the broth, heavy cream, and the reserved pasta water into the pan. Add the cream cheese and stir till melted. Increase the heat and allow the mixture to simmer for 4 to 6 minutes to thicken.

Add the cooked pasta to the sauce and stir to combine. Add in the chopped parsley, shrimp, and sausage and stir.

Top with optional Parmesan. Serve immediately.