Grease a box mould (approx. 1 1/4 litre capacity; 26 cm long) and sprinkle with sugar. Preheat the oven (electric cooker: 175°C/circulating air: 150°C/gas: level 2). Coarsely chop nuts and chocolate separately.
Mix eggs, sugar, vanilla sugar and oil with the whisk of the mixer for 4-5 minutes.
Peel the bananas, cut them into fine slices and immediately fold them into the dough. Mix baking powder, flour, salt and cinnamon and stir in briefly with the milk. Stir in the milk. Fold in 100 g nuts and the chocolate.
Fill the dough into the form, smooth it down. Sprinkle with remaining nuts.
Bake in a hot oven for about 1 hour. After approx. 50 minutes check if the cake is baked through. If there is still some sticky dough sticking to the spit, bake the cake for 5-10 minutes. But do not bake too long, the cake should still be juicy.
Let the cake cool in the mould for 15-20 minutes. Then use a knife to remove the cake from the edge of the tin and turn it out of the tin. Let it cool down. Dust with icing sugar. Whipped cream tastes good with it.