Start by coating the chicken breasts with olive oil in a large mixing bowl. Sprinkle in Cajun seasoning, garlic powder, onion powder, smoked paprika, salt, and black pepper. Ensure the chicken is evenly coated, which should take about 5 minutes.

Heat a skillet over medium heat and add the seasoned chicken breasts. Sear them for 2–3 minutes per side until they develop a golden-brown color.

Place the browned chicken in the crock pot and layer the sliced bell pepper, chopped onion, and minced garlic over the top.

Pour the diced tomatoes (with juice) and chicken broth into the slow cooker, scraping the skillet with a wooden spoon to capture any flavorful brown bits stuck to the bottom.

Cover the slow cooker and set it to low for 4-5 hours or high for 2-3 hours.

Once cooked, carefully remove the chicken from the slow cooker and shred it using two forks.

Stir in the heavy cream and Parmesan cheese, allowing them to melt and blend into the sauce.

While the flavors meld in the slow cooker, cook the penne pasta according to package instructions until al dente.

Once the sauce is creamy and the pasta is cooked, add the penne to the slow cooker and stir gently to combine everything.

Spoon the finished dish onto plates and garnish with fresh parsley before serving.