Cut squash in half; discard seeds. Place squash, cut side down, in a 15x10x1-in. baking pan. Fill pan with hot water to a depth of 1/2 in. Bake, uncovered, at 350° for 30 minutes.
Meanwhile, combine cranberries, apple, orange, brown sugar, walnuts, butter and orange zest. Drain water from pan; turn squash cut side up. Sprinkle with salt. Stuff with cranberry mixture. Bake 25 minutes longer or until squash is tender.