Preheat oven to 400°F. Line a baking sheet with foil, spray the foil with cooking spray. Cut each squash into quarters lengthwise, remove and discard seeds and membranes. Sprinkle evenly with salt and pepper.
Place squash cut side down on foil lined baking sheet. Bake for 45 min or until squash is tender.
Combine butter, brown sugar and nutmeg. Turn squash, cut sides up on baking sheet, Sprinkle evenly with butter mix. Bake 5 min more or until brown.