01 - Place chicken breasts in the bottom of the slow cooker in a single layer, ensuring even distribution for consistent cooking.
02 - In a medium bowl, whisk together chicken broth, heavy cream, Parmesan, garlic, Italian seasoning, onion powder, salt, and pepper until thoroughly combined and smooth.
03 - Pour the sauce mixture evenly over the chicken, ensuring all pieces are coated.
04 - Cover and cook on low for 4-6 hours or on high for 2-3 hours until chicken reaches internal temperature of 165°F and is tender.
05 - Optional: During the last 30 minutes, whisk cornstarch and water to form a slurry. Stir into the slow cooker and continue cooking until sauce thickens.
06 - Transfer chicken to plates, top with creamy sauce, and garnish with chopped fresh parsley.