For the sponge cake and a 24 cm in diameter pan:5 middle-sized eggs200 g of sugar130 g of potato starch40 g of cocoa powder5 g of baking powderFor soaking:100 ml of strong sweet coffeeFor the cream:250 ml of heavy whipping cream150 ml of strong coffee30 g of icing sugar7 g of gelatinFor decoration:200 ml of heavy whipping creamgrated chocolatecoffee beansThe cake is 1.2 kgThe original book recipe:For the sponge cake:5 eggs200 g of sugar8 tbsp of potato starch (1 tbsp = 16 g)3 tbsp of cocoa powder1 tsp of baking powderFor soaking:strong sweet coffeeFor the cream:1/4 liter of heavy whipping cream3/4 cup of strong coffee2 tbsp of sugar2 tsp of gelatinFor decoration:1/2 cup of heavy whipping creamcoffee beans