Why Were My Forgotten Cookies Sticky?

Our answer

Nigella's Forgotten Cookies) (from AT MY TABLE) are meringues that are studded with chocolate chips and chopped pistachio nuts. They are put into a preheated oven, then the heat is turned off and the meringues are left to dry overnight in the cooling oven. The resulting cookies should have a dry, crisp shell with a soft interior. However, like regular meringues they can be affected by humid conditions. Meringue is mostly sugar and as sugar is hygroscopic it will attract moisture from the surrounding air, so meringues can remain sticky if the kitchen air is humid. Humid air is most commonly associated with warmer climates but if it is cold and wet or if the heating is turned up to high then you may also see higher levels of humidity in the kitchen.

Also make sure that the oven is really properly preheated before you put the cookies in and do not open the door until the next morning or until the oven is completely cold if you are making the cookies during the day (we would allow 8 hours). If you find that humidity has affected your cookies then you can put them back into an oven preheated to 120c (100c Fan/250F) for 30 minutes then switch off the oven and let the cookies cool in the oven for 30 minutes before removing them. Bear in mind also that in humid conditions the cookies will soften more quickly when they are stored.