For the banana cake, chop 200 g walnuts. Mix 500 g flour, 1 packet baking powder, 1/2 teaspoon salt and nuts. Peel the bananas. Finely puree 120 ml milk, 180 ml oil, 180 ml honey, vanillin sugar and bananas.
Slightly mix the flour mixture and the banana mixture and put it into a greased springform pan (26 cm Ø) sprinkled with flour. In a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see
manufacturer) bake for about 40 minutes.
Shortly before the end of the baking time of the banana cake for the chocolate cake, mix 500 g flour, cocoa powder, 1 packet of baking powder and 1/2 teaspoon salt and sieve. Mix maple syrup, 600 ml milk, 180 ml oil and vinegar.
Mix dry and wet ingredients. Pour into a greased springform pan (26 cm Ø) sprinkled with flour. Remove the finished banana cake. Bake the chocolate cake at the same temperature for about 45 minutes.
Let finished cakes rest briefly in the moulds, remove from the moulds and allow to cool.
Chopping chocolate. Bring 400 ml milk to the boil, remove from the heat, add chocolate and melt in the hot milk while stirring. Roast 150 g nuts in a pan while turning. Add 60 ml honey and glaze the nuts briefly in it.
Cut both cakes in half horizontally. Glue the cake bases alternately with 1/4 chocolate sauce each. Pour the remaining 1/4 of the sauce on the cake and spread nuts on top.