# Whisk the eggs with granulated sugar
until the mixture turns white, add yogurt
, vegetable oil, flour
, vanilla, baking powder, cocoa
in it and mix to get a smooth mixture.
# Grease a small rectangle shaped oven tray, and pour the cake mixture on it.
# Cook in the oven, which is preheated to 347 F for a while, for 30 minutes.
# Reverse the cake on a paper while it is still hot, make a roll by the help of the paper before it starts to cool down, and then let it cool down.
# Flatten the cake slowly and take paper off.
# Whisk the icing sugar
with 1 cup cold milk
, add cocoa
# Pour half of the cream on the flattened cake, and flat the cream, place the banana
in the middle and roll the cake again.
# Cover the cake with the remaining cream, drizzle finely sliced hazelnut
pieces all over. Refrigerate for about 4-5 hours.