Heat olive oil in a large deep skillet or Dutch oven over medium heat.
Add the sliced chicken sausage to the skillet and cook for 5-6 minutes, stirring occasionally, until browned and cooked through. Remove the sausage from the skillet and set aside.
In the same skillet, add the diced green bell pepper, red bell pepper, and onion. Cook for 4-5 minutes until the vegetables are softened.
Add the minced garlic, Cajun seasoning, smoked paprika, and cayenne pepper to the skillet. Stir and cook for 1 minute until fragrant.
Pour in the chicken broth and heavy cream, stirring to combine.
Add the penne pasta to the skillet and bring the mixture to a simmer.
Cover and cook for 12-15 minutes, stirring occasionally, until the pasta is tender and most of the liquid is absorbed.
Return the cooked chicken sausage to the skillet and stir to combine.
Add the shredded cheddar cheese and grated Parmesan cheese. Stir until the cheese is melted and the sauce is creamy.
Season with salt and freshly ground black pepper to taste.
Remove from heat and garnish with chopped fresh parsley before serving.