Vanilla Glace Icing Recipe ~ It dries shiny and stays fairly soft (unlike royal icing), but it still able to be stacked without the cookies sticking to each other. BUT it takes 24 hours to dry completely. Tastes infinitely better than royal icing.
To make your own henna cookies, you need a bad-ass recipe for royal icing. I used the recipe from The Art of the Cookie, a must have for your cookbook collection. There are gorgeous photos and the recipes are outstanding.
Easy royal icing recipe with three ingredients: meringue powder, confectioners’ sugar and water. This smooth, hard-drying icing is perfect for making decorations in advance and that last. It is also useful as a "cement" to fasten decorations together.
Decorating with Royal Icing: Recipe and Step-by-Step Tutorial – Annie’s Eats. When icing is not in use, put it in a jar tip down with a little bit of water to prevent the icing in the tip from clogging.