In a roasting pan, toss 3 cups of squash, orange juice and brown sugar; add cinnamon. Cover and bake at 450° for 30-40 minutes or until squash is tender. Discard cinnamon; drain squash, reserving cooking liquid. Set squash and liquid aside.
In a Dutch oven, saute the leeks, apple and onion in butter until tender. Add broth; bring to a boil. Stir in cooked squash; cook for 5 minutes. Add the cream, salt and pepper; heat through. Cool slightly.
In a blender, process soup in batches until smooth. Return all to the pan; heat through (do not boil).
Cut remaining squash into 1/4-in. cubes. In a large skillet, saute squash cubes in oil and reserved cooking liquid until squash is tender and liquid has evaporated. Ladle soup into bowls. Garnish with squash cubes. Yield: 6 servings.