Combine cake mix, water and egg in a mixing bowl. Mix well and pour into an ungreased 8"x8" baking pan. Bake at 350 degrees for 35 to 40 minutes, or until a toothpick inserted near the center comes out clean. Cool for 10 minutes; turn out of pan onto a wire rack. When completely cooled, crumble cake and set aside, reserving 1/4 cup crumbs for garnish. Whisk together milk and pudding mixes in a bowl for 2 minutes, or until slightly thickened. Let stand for 2 minutes, or until softly set. Stir in pumpkin and spices; mix well. In a trifle bowl or 3-1/2 quart glass serving bowl, layer one-quarter of the cake crumbs, one-half of pudding mixture, one-quarter of crumbs and one-half of whiipped topping. Repeat layers, ending with topping. Garnish with reserved cake crumbs. Serve immediately or refrigerate. Serves 18.