Mix all the ingredients with an electric whisk until they form a fluffy but fluid mixture. Place the bowl to one side.
Beat the egg white with the sugar until stiff, sieve in the flour, and then carefully fold in 3 tbsp of the egg yolk mix you prepared before.
Transfer this batter into a piping bag and use it to pipe out a giraffe-print pattern onto a deep baking tray lined with parchment paper. Then bake the whole thing in a preheated oven for just 1 minute at 360°F with the heat coming from above and below.
Mix the egg white, sugar, and baking powder, then add the rest of the egg yolk batter, as well as the cocoa powder. Stir everything into a smooth batter and distribute it evenly on top of the giraffe pattern. Then bake the cake together for 15 minutes, again at 360°F, heated from above and below.
Sprinkle a clean dish cloth with sugar and turn the cake out on to it. Pull away the parchment paper and cover the cake with a second, damp, dish cloth. Let it cool down and turn it over with the help of the cloths.
Beat the whipping cream with the powdered sugar until stiff. Carefully mix in the cream cheese and then spread the mixture evenly over the cake.
Roll the two peeled bananas up in the cake.
Your wonder roll is complete!
