The very best recipes come from friends and relations. This one is no exception. Deborah, my New York sister-in-law and dessert-maker extraordinaire, sent me this irresistible gingersnap recipe a few years ago. She was given it by her friend, Helen Freytag, who once lived in Hong Kong, and she had received it from…well, who knows? A chain of deliciousness—as Nigella might say—stretching across the country and perhaps even the world.