Bake the gingerbread according to the package, cool. Meanwhile, prepare the pudding and set aside to cool. Stir in pumpkin pie filling, sugar and cinnamon into pudding. Crumble 1 batch of gingerbread into the bottom of a large pretty bowl. Pour 1/2 of the pudding mixture over the gingerbread, then add a layer of whipped topping. Repeat with remaining gingerbread, pudding and whipped topping. Sprinkle the top with crushed gingersnaps. Refrigerate overnight.