Add the butter, olive oil, and onion to a large pot over medium-high heat and cook for 3-4 minutes, or until the onions become translucent.
Add the red bell peppers, garlic, Cajun seasoning, basil, paprika, ground black pepper, salt, and cayenne pepper. Stir to combine and cook for 3 more minutes or until the bell pepper starts to become soft.
Add the parmesan, heavy cream, cream cheese, and vegetable broth and stir and cook for 8-10 minutes or until the sauce starts to thicken and the cream cheese has fully melted.
Add the cooked and drained pasta and stir to coat pasta with sauce. Cook for 2-3 minutes, then serve with freshly chopped parsley on top, if desired.
Notes
**Cayenne Pepper and Cajun spices : If you like heat, start by adding 1/4 teaspoon cayenne pepper and taste the sauce. Remember you can always add more cayenne pepper, but you can’t take it out!