Dostoevsky loved it. Catherine the Great enjoyed it. Sofia Tolstaya, Tolstoy’s long-suffering wife and assistant, made it. It was once the quintessential Russian dessert: pastila. Sweet, fluffy pastila became a classic afternoon tea snack at aristocratic Russian soirees of the 19th century. To make it, apple puree—essentially, applesauce—egg whites, and sugar are leavened with lots and lots of air that’s forced into the mixture with hard whisking. What happens next is improbable but stunning. The earthy apple gloop transforms into a gleaming white cloud, as light and soft as a…
