Chocolate Sponge Cake with Blueberries

This delicious sponge cake is served on birthdays in Ukraine. Sour cherries, blackberries, raspberries, strawberries, nectarines, or peaches are all delicious substitutes for the blueberries. Cognac or brandy are the traditional accompaniments, but if it is not to your liking, experiment with other flavors such as: anisette, kirsch (cherry), framboise (raspberry), Poire William (pear), or fraise (strawberry)—and if serving children or those who do not imbibe, eliminate the liqueur completel