1. Pierce squash with a knife in several places. Place squash directly on middle rack in oven.
2. Bake at 350° for 45 minutes or until just tender. Remove from oven; cool.
3. Cut each squash in half; remove and discard seeds. Cut each half into two wedges. Arrange, skin side down, on a lightly greased roasting pan. Brush cut sides with shortening. Season with salt and pepper to taste.
4. Combine cheese and raisins. Top each squash wedge with cheese mixture, and sprinkle evenly with breadcrumbs; drizzle with remaining shortening.
5. Bake at 350° for 20 minutes or until cheese is melted and golden. Garnish, if desired.