Preheat oven to 450F (230C). Line a rimmed baking sheet with foil and spray with cooking spray.
Scrub the outside of the potatoes until they are clean, and prick each potato with a fork a few times to allow steam to escape during cooking.
Place potatoes on a microwave-safe plate and microwave 2 at a time for approximately 5-10 minutes, or until tender. Let cool for 5 minutes.
Meanwhile, in a large bowl, stir together chicken, sour cream, broccoli, 1 cup of the cheese, garlic powder, onion powder, salt, and pepper.
Cut potatoes in half lengthwise. Scoop the inside of the potato out of the peel, leaving a thin layer of potato inside. Set aside the flesh that you just removed and use it for a separate meal, if desired.
Spray the potato skins with cooking spray, place on the baking sheet, and bake for about 5-7 minutes (or until outsides are slightly crispy).
Remove potato skins from the oven and stuff with chicken mixture. Sprinkle remaining cheese over top.
Turn oven to “broil.” Place the stuffed potatoes under the broiler for 2-3 minutes, or until cheese is melted and chicken is heated through.