Slice the turkey sausage into bite-sized rounds. Dice the bell pepper and onion finely, and mince the garlic cloves.
Heat the olive oil over medium-high heat in your large skillet. Add the turkey sausage slices and cook until browned on both sides, about 5-7 minutes. Remove the sausage and set aside.
In the same pan, add the diced onion and bell pepper. Sauté for 4-5 minutes until softened and fragrant. Add minced garlic and cook for 30 seconds.
Sprinkle Cajun seasoning, smoked paprika, and cayenne pepper (if using). Stir and toast spices for about 1 minute. Pour in chicken broth and deglaze the pan, scraping browned bits. Return sausage to pan.
Add penne pasta and stir. Reduce heat to medium-low, cover with lid, and simmer for 10-12 minutes until pasta is tender, stirring occasionally.
Slowly pour in heavy cream and stir. Add shredded mozzarella cheese and stir until melted and sauce is creamy. Season with salt and pepper to taste.
Sprinkle chopped fresh parsley over the top for garnish. Serve immediately.