If they are unrefrigerated, no bake cookies are best eaten within 3 days. Just make sure to keep them in an airtight container. If they are refrigerated in an airtight container, they will last about 10 days. No Bake Cookies can be frozen by placing in a freezer bag and separating layers with wax paper so they don't stick together. They will keep for up to 3 months. Defrost on the counter top or in the refrigerator.