Scrub squash; halve lengthwise and remove seeds. Place halves, cut side up, in a large roasting pan. In a mixing bowl combine brown sugar, molasses, margarine or butter, orange peel, cinnamon, and cloves. Spoon mixture into squash halves. Bake, covered, in a 350 degree F. oven for 40 minutes.
Stir brown sugar mixture; uncover and bake 15 minutes more or until squash is tender. Sprinkle with additional brown sugar and ground cloves, and garnish with orange peel curls, if desired. Makes 6 side-dish servings.