In a liquid measure, combine boiling water and gelatin powder. Mix until gelatin is completely dissolved. Stir in cold water. Pour into 13 "x 9" pan. Refrigerate three hours, or until firm. Cut into 1/2" cubes. In a mixing bowl, combine milk, pudding mixes, and cinnamon. Mix until thickened. Fold in two cups of the whipped topping. Mix until smooth. Layer half of the remaining gelatin cubes, cake cubes, oranges and pudding mixture in 3-quart serving bowl. Repeat layers once. Garnish with remaining whipped topping. Store leftover dessert in refrigerator.