Grease a box mould (26 cm long) and sprinkle with sugar. Coarsely chop nuts, seeds and chocolate separately. Mix eggs, sugar, vanilla sugar and oil with the whisk of the hand mixer for about 3 minutes
Peel the bananas, weigh 300 g fruit flesh, cut into fine slices and fold into the dough. Mix flour, cocoa, baking powder, salt and cinnamon and stir in briefly, alternating with the milk. Fold in 3/4 of each of the chocolate and nuts. Fill the dough into the form, smooth it down
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 1 1/4 hours. Cover with aluminium foil after about 30 minutes. Take the cake out of the oven, place it on a cake rack and let it cool in the tin for about 20 minutes. Loosen the rim with a knife and turn out of the tin. Let it cool down
Melt the rest of the chocolate over a warm water bath and run in lines over the cake. Sprinkle with remaining nuts. Let the chocolate set. Arrange the cake with grapes and apples on a plate
Waiting time approx. 1 hour