Butternut Squash Gratin

Heat oven to 450°F. Spray 17x12-inch half-sheet pan with cooking spray. Cut butternut and spaghetti squash in half lengthwise; discard seeds. Place squash, cut sides up, in pan. Drizzle with melted butter; sprinkle with 1/2 cup of the brown sugar. Bake 40 minutes or until tender. Cool 20 minutes.

With fork, scrape inside of spaghetti squash to remove spaghetti-like strands; place in large bowl. Scoop pulp from butternut squash; coarsely chop pulp. Toss with spaghetti squash.

In heavy nonaluminum saucepan, heat whipping cream over medium heat 5 minutes, stirring frequently, just until it begins to steam (do not boil); remove from heat. In small bowl, mix cinnamon, nutmeg and remaining 1/2 cup brown sugar; set aside.

Butter 13x9-inch (3-quart) glass baking dish. Arrange one-fourth of the potato slices in baking dish. Top with one-third of the squash mixture; sprinkle with 1/4 teaspoon of the salt, 1/4 teaspoon of the pepper and 1 cup of the cheese. Pour 3/4 cup hot cream over top. Repeat layers twice, sprinkling one-third of reserved brown sugar mixture over each of second and third squash layers. Top with remaining potato slices, 1/4 teaspoon salt and 1/4 teaspoon pepper. Gently press layers down with back of spoon. Sprinkle with remaining 1 cup cheese; pour remaining 3/4 cup hot cream over top. Sprinkle with remaining brown sugar mixture. Line cookie sheet with foil. Place baking dish on cookie sheet.

Cover; bake 1 hour. Uncover; bake 25 minutes longer or until top is golden brown and potatoes are tender. Cool 20 minutes before serving. Garnish with rosemary.