In the slow cooker, place the chicken breasts and season them with salt, pepper, and garlic powder.
In a medium bowl, mix together the cream cheese, chicken broth, ranch dressing mix, and cream of chicken soup until well blended.
Pour the cream cheese mixture over the chicken in the slow cooker, ensuring the chicken is well coated.
Cover the slow cooker with a lid and cook on low for 6-7 hours or on high for 4-5 hours, or until the chicken is cooked through and tender.
About 30 minutes before serving, shred the chicken directly in the slow cooker using two forks.
Stir in the shredded cheddar cheese and frozen peas (if using), mixing well to combine. Let it cook for an additional 30 minutes on low until the cheese melts and the peas are heated through.
Taste and adjust seasoning with more salt and pepper if needed.
Serve hot, garnished with fresh parsley for a burst of color.