In a large bowl, combine the boneless, skinless chicken breasts with olive oil, Cajun seasoning, garlic powder, onion powder, smoked paprika, salt, and black pepper. Make sure to rub the spices well into the chicken.

Heat a skillet over medium heat and add the seasoned chicken. Sear each side for 2-3 minutes until browned and fragrant. Once browned, transfer the chicken to your slow cooker.

In the slow cooker, layer sliced bell peppers, onion, and minced garlic over the browned chicken.

Pour in the diced tomatoes and chicken broth, scraping any remaining bits from the skillet into the crock pot. Ensure everything is well combined.

Cover the slow cooker and cook on low for 4-5 hours or on high for 2-3 hours until the chicken is tender and fully cooked.

Once cooked, remove the chicken from the slow cooker and shred it using two forks. Return it back into the pot, mixing it gently with the vegetables and sauce.

Stir in the heavy cream and grated Parmesan cheese until melted and creamy. Let it simmer for a few minutes.

While the sauce is melding together, cook the penne pasta according to the package instructions until al dente. Drain the pasta and set aside.

Add the cooked and drained penne pasta to the slow cooker. Gently mix until the pasta is coated in the creamy sauce.

Allow the pasta to heat in the slow cooker for another 15-20 minutes. Serve hot and garnish with freshly chopped parsley.