Wash squash, cut off ends and cut each squash in half crosswise. Remove seeds and loose fibers. Place cut side down, in shallow baking pan.
Bake at 350°F about 45 minutes or until squash is starting to soften. Meanwhile, in medium fry pan, saute' celery and onions in margarine.
In large mixing bowl, combine bread cubes, KELLOGG'S ALL-BRAN cereal, salt and poultry seasoning. Add celery mixture, chopped apples and raisins, tossing gently. Stir in broth, mixing until evenly combined.
Cut each hot squash into 4 rings about 1 1/4-inches thick. Place back into shallow baking pan, in single layer. Fill each ring with about 1/2 cup stuffing. Cover pan with foil.
Bake at 350°F about 35 minutes or until squash is tender. Garnish stuffed squash with apple slices and sugar. Broil 3 minutes or until sugar bubbles or browns.