Preheat the oven for the banana cake (electric oven: 175 °C/circulating air: 150 °C/gas: see manufacturer). Grease a springform pan (26 cm Ø) and dust with flour. Chop 200 g walnuts. Mix 500 g flour, 1 packet baking powder, 1⁄2 tsp salt and chopped nuts.
Peel bananas. Finely puree with 1⁄8 l milk, 180 ml oil, 240 g honey and vanilla sugar. Gently mix flour and banana mixture and pour into the springform pan. Bake in a hot oven for about 40 minutes.
Then remove from the mould and allow to cool briefly. Then remove from the mould and let it cool down.
For the chocolate cake clean the springform pan, grease it again and dust it with flour. Mix 500 g flour, 1 sachet baking powder, 1⁄2 TL salt and baking cocoa and sieve. maple syrup, 600 ml milk, 180 ml oil and food
Mix flour and milk mixture briefly. Fill the dough into the tin and bake at the same temperature in a hot oven for about 45 minutes. Then remove from the oven and allow to cool briefly in the mould. Then remove from the mould and let it cool down.
Break chocolate into pieces. Bring 400 ml milk to the boil and remove from the stove. Add chocolate and melt in the hot milk while stirring. Roast 150 g nuts in a pan without fat. Add 80 g honey and caramelise the nuts all around.
Cut both cakes in half horizontally. Assemble the cake bases alternately with 1⁄4 chocolate sauce. Finally, spread 1⁄4 sauce over the cake, sprinkle with the caramelized nuts.