Cook the Pasta:
Bring a large pot of salted water to a boil. Add the penne pasta and cook according to the package instructions, usually about 10-12 minutes, until al dente. Drain the pasta, reserving about 1/2 cup of pasta water for later use.

Cook the Sausage:
While the pasta is cooking, heat olive oil in a large skillet or pan over medium heat. Add the sliced smoked sausage and cook for 5-7 minutes, stirring occasionally, until the sausage is browned and slightly crispy on the edges. Remove the sausage from the skillet and set aside.

Sauté the Vegetables:
In the same skillet, add the chopped onion and bell pepper. Sauté for about 3-4 minutes until the vegetables are softened and lightly caramelized. Add the minced garlic and cook for another 1 minute until fragrant.

Add the Tomatoes and Liquids:
Stir in the diced tomatoes, heavy cream, and chicken broth. Bring the mixture to a simmer. As it simmers, stir in the Cajun seasoning, paprika, thyme, cayenne pepper (if using), and season with salt and pepper. Let it cook for about 5 minutes, allowing the sauce to thicken slightly.

Combine the Sausage and Pasta:
Return the cooked sausage to the skillet and stir to combine. Add the drained pasta to the sauce and toss everything together to coat the pasta in the creamy Cajun sauce. If the sauce seems too thick, add a bit of the reserved pasta water to reach your desired consistency.

Add Cheese and Garnish:
Stir in the freshly grated Parmesan cheese, allowing it to melt and add richness to the sauce. Taste and adjust seasoning as needed. Garnish with fresh parsley for a pop of color and a hint of freshness.

Serve:
Serve the Cajun sausage pasta in bowls or on plates, and enjoy the bold, creamy goodness. Pair with a side salad or garlic bread for a complete meal!