Bird's milk is a type of custard/cream. You can find it in many candies, called Bird's Milk, sold within the Slavic markets. It is also common, within the Slavic tradition, to make Bird Milk Jello or Bird's Milk Cakes for holiday dinners.
This cake was inspired by a friend of mine on Facebook. It was a complete blast making it; and believe it or not, it was quite easy.