Not only are these cookies yummy melt-in-your-mouth, but they are also gluten free and dairy free.
Meringue Cookiesegg whites
sugar to equal volume of egg whites
splash of vanilla (or other flavor)
Heat oven to 400 degrees F.
Whip egg whites and vanilla until frothy. Slowly add sugar as you continue whipping egg whites. Stop when the egg whites can form a stiff peak.
Drop by teaspoonful onto cookie sheets covered with parchment paper.
Turn off oven and put cookies in. Leave them in a long time. Like all day. Every now and then check on the cookies. If the oven has cooled, turn it on as low as it will go (170 for my oven) for 10-20 min. Leave them in overnight if you can.
What you're doing is essentially drying the cookies out. Test them as you go. When the cookie is hard and dry (not chewy, and not weeping) it's done. It will be crisp to bite, but melt in your mouth if you don't chew.
Notes and modifications:
I've forgotten the vanilla and they're still pretty good.
You can try other flavorings. I liked almond extract. The orange extract just tasted vaguely citrus. Rum was uniformly awful. I haven't tried mint yet, but that might be an interesting Christmas experiment.