In a large bowl, combine the chicken with olive oil, Cajun seasoning, garlic powder, onion powder, smoked paprika, salt, and black pepper. Coat the chicken thoroughly.

Heat a skillet over medium-high heat. Sear the chicken breasts for 2-3 minutes on each side until golden brown. Transfer to slow cooker.

Layer sliced bell peppers, onion wedges, and minced garlic on top of the chicken in the slow cooker.

Pour diced tomatoes and chicken broth over the layered ingredients. Scrape any bits from the skillet for added flavor.

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

Remove chicken from the slow cooker and shred into bite-sized pieces.

Stir in heavy cream and grated Parmesan cheese until melted and creamy.

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

Stir cooked pasta into the slow cooker, mixing thoroughly. Let heat together for an additional 15-20 minutes.

Ladle into bowls and garnish with fresh parsley before serving. Enjoy warm.