Although it is a rare batch that lasts more than a few days without being devoured down to the very last crumb, cookies can stale quickly unless protected against air or excess moisture. Proper storage also prevents them from breakage or other damage.
Let cookies cool completely, then arrange in an airtight container as shown in the accompanying step. They will keep at room temperature for up to 3 days. If you prefer, leave bar cookies in their baking pan, tightly covered with plastic wrap or aluminum foil. Store soft and crisp cookies separately, or the crisp ones will absorb moisture from the others and become soft themselves. On the other hand, you can revive soft cookies that have dried out and hardened by placing a wedge of apple or a slice of bread on a piece of waxed paper and setting it on top of the cookies in the closed container. Remove after 1 day.
For longer storage, freeze unfrosted cookies in heavy-duty freezer bags or freezer containers. They will stay fresh up to 1 year. When needed, thaw and decorate.
Select a storage container that allows easy access to the cookies inside. Arrange the cookies in layers in the container. If the cookies are soft, place a sheet of waxed paper between each layer. Seal the container airtight.