In French, this pan is known as langue-de-chat.
Additional ingredients may include chocolate, citrus, and spices.
Beat in the egg whites one at a time.
Because of the dry nature and ingredients used, these biscuits can be kept for quite a long time and are usually served with certain liqueurs and sparkling wines.
In the original recipe, they are baked at 220C fan.
They are produced from , , , sometimes and.