Spray slow cooker with non-stick cooking spray (optional) and set aside.
Place the chicken breasts in the bottom of the slow cooker. Season them with half of the salt and pepper, half of the paprika and rosemary , drizzle half of the maple syrup over the chicken and cover them with all of the chopped onion.
Add the cubed sweet potatoes on top of the chicken. Season with the remaining half of the salt and pepper, paprika and rosemary and maple syrup.
Divide the cream cheese into 4 to 5 pats and distribute it evenly over the top of the sweet potatoes.
Cover and cook on LOW for 7 to 8 hours or until the sweet potatoes are tender and the internal temperature of the chicken registers 165° F on an instant read meat thermometer.
Carefully stir the melted cream cheese into the dish. Garnish with additional ground paprika and dried rosemary if desired before serving.