In a large pot or Dutch oven, heat a splash of olive oil over medium heat. Add the sliced sausage and cook until browned, about 5-7 minutes.

Add the chopped onion and bell pepper to the pot. Sauté until they soften, roughly 3-4 minutes. Stir in the minced garlic and cook for an additional minute until fragrant.

Pour in the chicken broth and diced tomatoes (with juices). Stir in the penne pasta, ensuring it's submerged in the liquid. Bring to a gentle boil.

Reduce the heat to a simmer and cover the pot. Cook for about 12-15 minutes, stirring occasionally until the pasta is al dente and has absorbed most of the liquid.

Once the pasta is cooked, lower the heat and stir in the heavy cream, Cajun seasoning, smoked paprika, salt, and pepper. Keep stirring until everything is well-combined and warmed through.

Serve in bowls, garnished with fresh parsley and a sprinkle of grated Parmesan cheese, if desired.