~Preheat oven to 400 degrees. Butter 13x9x2" glass baking sidh. Stir in butter, maple syrup and apple juice in small saucepan over medium-low heat until butter melts. Increase heat and boil until mixture is slightly reduced, about 5 minutes. Remove from heat; whisk in cinnamon, allspice and salt.

~Arrange 1/3 of squash slices in prepared dish. Top iwth half of apple slices, and the 1/3 of squash slices. Arrange remaining slices of squash and apple atop, alternating squash and apples slices and overlapping slightly. Sprinkle lightly with salt and pepper. Pour maple syrup mixture over. Cover baking dish tightly with foil.

~Bake casserole until squash is almost tender, about 590 minutes. Uncover and bake until squash is tender, basting occasionally with syrup, about 20 minutes longer. (Can be made 1 day ahead. Cover with foil and refrigerate. Rewarm, covered, in 350 degree oven about 25 minutes, or microwave on high about 8 minutes.) Spoon syrup from dish over vegetables and serve.