Begin by seasoning the chicken breasts with the olive oil, Cajun seasoning, garlic powder, onion powder, smoked paprika, salt, and black pepper. Let it marinate while you prepare the next steps.

Heat a skillet over medium-high heat and add a little olive oil. Sear the seasoned chicken breasts for 2-3 minutes on each side until golden-brown.

Once browned, transfer the chicken to the slow cooker in a single layer.

Layer the sliced bell pepper, thinly sliced onion, and minced garlic over the chicken.

Pour the diced tomatoes and their juices over the vegetables and chicken, followed by the chicken broth.

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

Remove the chicken and shred into bite-sized pieces. Return it to the slow cooker.

Stir in the heavy cream and grated Parmesan cheese until fully incorporated.

Cook the penne pasta according to package instructions, then drain.

Add the cooked pasta to the slow cooker and gently fold it into the creamy chicken mixture. Heat through for 15-20 minutes.

Spoon portions onto plates and garnish with chopped parsley. Serve hot.