These lightened-up ghostly Halloween cookies are scary cute! Serve these meringue cookies as-is for a fun Halloween treat, or use them to top a Halloween cake. When making meringues, make sure that your bowl and beaters are clean and that there is not a trace of yolk in the egg white; the smallest amount of fat will prevent the egg whites from forming meringue. Depending on the humidity in your kitchen, the baking time might vary considerably. Check to make sure your cookies are crisp throughout before removing them from the oven.