1. Bring a large pot of salted water to a boil and cook the penne until al dente. Reserve 1 cup of pasta water, then drain and set aside.

2. Season the chicken pieces with Cajun seasoning and garlic powder until evenly coated.

3. Heat olive oil in a large skillet over medium-high heat, then cook the chicken for 5 to 7 minutes until browned and cooked through. Transfer it to a plate.

4. In the same skillet, cook the onion and red bell pepper for 3 to 4 minutes until softened. Add the garlic and cook for 30 seconds.

5. Pour in the chicken broth and heavy cream, then stir in the butter, salt, black pepper, and Parmesan cheese until the sauce is smooth and creamy.

6. Return the chicken to the skillet and add the cooked pasta. Toss everything together until well coated, adding a little reserved pasta water if needed.

7. Sprinkle with chopped parsley and serve hot with extra Parmesan if desired.