Preheat your oven to 375 degrees F (190 degrees C).

Cook penne or rotini in well-salted boiling water until just al dente, about 1 to 2 minutes less than the package suggests. Drain and set aside.

Heat olive oil in a large skillet over medium heat. Add cubed chicken and Cajun seasoning. Cook for 5 to 7 minutes, letting pieces sit undisturbed for a couple minutes to develop a crust. Remove and set aside.

In the same skillet, saute diced onion, red bell pepper, and minced garlic for 3 to 4 minutes until softened and fragrant.

Reduce heat to medium-low. Stir in softened cream cheese until fully melted. Pour in heavy cream and chicken broth, stirring steadily to form a smooth sauce.

Stir in shredded cheddar and Parmesan cheese until fully melted and creamy. Taste and adjust salt, pepper, and Cajun seasoning.

Return browned chicken to the skillet and add drained pasta. Fold together gently until everything is evenly coated.

Transfer to a greased 9x13-inch baking dish, spreading evenly. Bake for 20 to 25 minutes until bubbly and golden brown on top.

Rest for 5 minutes before serving. Garnish with chopped fresh parsley if desired and serve hot.