In a medium bowl, combine the stuffing mix, melted butter, garlic powder, onion powder, and black pepper. Stir until the stuffing is evenly coated.
Pour the stuffing mixture evenly into the bottom of the crock pot, spreading it out in an even layer.
Place the chicken breasts on top of the stuffing layer in the crock pot.
In a separate bowl, whisk together the condensed cream of mushroom soup and chicken broth until smooth.
Pour the soup mixture evenly over the chicken breasts and stuffing in the crock pot.
Cover the crock pot with the lid and cook on low for 4 hours, or until the chicken is cooked through and the stuffing is tender.
Once cooked, carefully remove the chicken breasts and fluff the stuffing with a fork before serving.