Preheat the oven to 180 degrees C or 355 degrees Fahrenheit. Beat the egg whites until stiff and set aside. Then beat the yolks and sugar until foamy. Once foamy, add in the milk and oil. Combine the flour and baking powder and sift and fold into the mixture. Lastly, fold in the stiff egg whites and spread out the batter onto a baking sheet covered in parchment paper. Bake for 20 minutes.

Heat milk until boiling, reserving just a little bit to whisk together with the cornstarch and sugar. Once boiling, remove from heat and whisk in the cornstarch-milk-sugar mixture. Return to a boil and let boil for 1 minute while whisking constantly. Lastly, stir in the vanilla and transfer to a bowl and cool in the fridge.

Beat the whipping cream until stiff peaks form. Dissolve the gelatine in 1/4 c of boiling water, then mix in 1/4 of the whipped cream and allow to cool some (store the whipped cream in the fridge in the meantime). Finally fold in with the remaining whipped cream and then the cooled pudding. You run the risk of having chunks form if you just pour the dissolved gelatine into the cold whipping cream.

Half the bananas and lay them on top of the baked cake. Spread on the pudding and whipped cream mixture. Finally melt the chocolate and butter in a hot waterbath until just melted, then spread on top of the cake using a knife or cake spatula. Transfer to the fridge until ready to cut and serve - will keep for a couple of days.