I was very sad when the box was empty and when I discovered I couldn't buy more online, I set out to make my own. It was much easier than I thought it would be. There are lots of recipes and tutorials out there for this type of cookie. Here is my favorite.
There are very few main ingredients. For a small batch you need: 1/2 cup of sugar, 2 1/2 tablespoons of flour, a dash of salt and an egg white.