Start by cooking the pasta according to the package instructions. Drain and set aside.
n a large zip-top bag, combine 3 teaspoons of Cajun seasoning, ¼ teaspoon salt, and ¼ teaspoon pepper. Add the chopped chicken to the bag, seal it, and shake until the chicken is well coated. Set aside.
Heat 2 tablespoons of butter in a large pan over medium heat. Once melted, add the seasoned chicken and cook until browned and fully cooked through (you may need to do this in batches). Remove the chicken from the pan and set it aside.
Add the remaining 1 tablespoon of butter to the pan. Once melted, add the diced onion and bell peppers. Cook, stirring frequently, until the vegetables begin to soften, about 3-5 minutes.
Pour in the heavy cream, followed by the smoked paprika, dried basil, garlic powder, remaining Cajun seasoning, and ¼ teaspoon salt and pepper. Bring the mixture to a boil, then lower the heat and let it simmer until the sauce thickens.
Return the cooked chicken to the pan and stir in the Parmesan cheese. Add the cooked pasta and toss everything together until the cheese melts and the pasta is coated with the creamy sauce.
Serve hot, and optionally top with fresh parsley for a pop of color.