1. Wash squash; cut in half crosswise.
2. Remove and discard seeds.
3. Place squash, cut side down, in a 13x9 baking dish.
4. Add hot water to dish to depth of 1/2 inch.
5. Bake, uncovered, at 400 for 30-40 minutes or until tender.
6. Drain and let cool slightly.
7. Scoop out pulp into a bowl, leaving 1/4 inch-thick shell.
8. Mash pulp.
9. Add orange juice concentrate, brown sugar, and allspice; stir well.
10. Cut a thin slice off bottom of each squash shell so it will sit flat.
11. Coat baking dish with cooking spray; return squash shells to dish.
12. Spoon squash mixture evenly into shells.
13. Combine corn flake crumbs, pecans, and margarine.
14. Sprinkle crumb mixture evenly over squash.
15. Bake, uncovered, at 400 for 15-20 minutes or until thoroughly heated.