Cook the Pasta: Bring a large pot of salted water to a boil and cook the penne pasta according to package instructions until al dente, about 8-10 minutes. Reserve 1/2 cup of pasta water, drain the pasta, and set aside.

Brown the Sausage: In a large skillet, heat 2 tablespoons of olive oil over medium-high heat. Add crumbled sausage and cook for 5-7 minutes until browned. Remove sausage and set aside.

Sauté the Vegetables: In the same skillet, add chopped onion and bell pepper, sauté for 3-4 minutes until softened. Stir in minced garlic and cook for 1 more minute.

Incorporate the Spices: Add Cajun seasoning, paprika, dried thyme, and optional red pepper flakes. Stir and cook for 1-2 minutes to bloom the spices.

Create the Sauce: Pour in chicken broth, bring to a simmer for 2-3 minutes. Add the heavy cream, stirring for 3-4 minutes until sauce thickens.

Combine Everything: Return sausage to skillet, add cooked pasta and mix well. Use reserved pasta water to adjust sauce thickness.

Season and Serve: Taste and season with salt and pepper. Garnish with parsley and Parmesan cheese if desired. Serve hot.