Cook the penne pasta to al dente according to package instructions. Drain and set aside.

Pound the chicken breasts to be an even thickness using a meat mallet or rolling pin.

In a bowl, combine the 1 tablespoon Cajun seasoning, paprika, garlic powder, onion powder, salt, and black pepper. Season the chicken with this mixture, ensuring they are evenly coated. Rub the mixture onto the chicken with your fingers to be sure it sticks.

In a large skillet, heat olive oil over medium-high heat. Add the seasoned chicken and cook until browned and cooked through. Remove the chicken breasts from the skillet and let them rest for about 5 minutes, then slice into strips.

In the same skillet, add a bit more olive oil if needed. Sauté the bell peppers and red onion until they are tender-crisp. Add the minced garlic and cook for 1 more minute.

Pour in the heavy cream and chicken broth, stirring to combine. Bring the mixture to a simmer.

Reduce the heat to low and gradually whisk in the Parmesan cheese until the sauce is smooth and creamy.

Add the remaining 1 teaspoon Cajun seasoning into the sauce and the sliced tomatoes and cook for 1 minute. Taste the sauce and adjust seasonings if desired.

Add the cooked penne pasta to the skillet, tossing everything together until the pasta is well coated in the creamy Cajun sauce.

Return the sliced chicken on top or mix it in with the sauce and noodles.