Separate the egg whites and yolks. Beat the egg yolks with powdered sugar while gradually adding oil and warm water to the foam. Beat the egg whites until stiff.
Sift the flour and mix it with the baking powder. Gently mix the egg white foam into the yolk foam and add the flour, mix lightly. Pour half of the light dough into a greased and floured banana bread baking form. Add cocoa to the remaining dough and mix. Pour the dough into the second baking mold and bake at a temperature of 355 °F / 180 °C for about half an hour. After baking, turn the dough out of the baking mold and let it cool.
Cut the cooled dough into thin strips.
Cook a thick pudding from milk, sugar, vanilla, vanilla pudding powder and let it cool. Beat the butter into a foam, gradually add the pudding and whip a smooth cream.
Alternately put pieces of light and dark dough together with the prepared cream. Leave a little cream for the top and sides of the cake.
Put it in the fridge for an hour and after an hour pour melted chocolate over the top. Cut with a sharp knife dipped in hot water. Cut with an oblique cut to have beautiful slices.