Preheat oven to 350º. Cut squash in half lengthwise, discarding seeds.
Place squash halves, cut side down, in a 13 x 9-inch baking dish and add water to a depth of 1/2 inch. Bake squash at 350º for 45 minutes or until squash is tender when pierced with a fork.
Remove squash from dish and cool. Scrape inside of squash with a fork to remove spaghetti-like strands. Top with your favorite sauce.