Bring a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente, usually about 8-10 minutes. Stir occasionally to prevent sticking.

Once cooked, drain the pasta in a colander and set aside. Do not rinse, as this will wash away the starch that helps the sauce adhere.

In a large skillet, heat the olive oil over medium heat. Add the sliced smoked sausage and cook until browned, about 5-7 minutes. This adds flavor and texture.

Add the diced onion, sliced bell peppers, and minced garlic to the skillet. Sauté for an additional 5-7 minutes until the vegetables are softened and fragrant.

Pour in the chicken broth and heavy cream into the skillet with the sausage and vegetables. Stir to combine.

Add the Cajun seasoning, salt, and black pepper. Stir well and let the mixture simmer for about 5 minutes, allowing the flavors to meld and the sauce to thicken slightly.

Add the cooked pasta to the skillet and toss to coat the pasta in the sauce. Cook for an additional 2-3 minutes to heat through.

Serve hot, garnished with grated Parmesan cheese and additional Cajun seasoning if desired.