Put the flour in a bowl. Make a depression in the middle and crumble yeast into it. Sprinkle 10 g sugar over it. Add 125 ml milk and mix. Cover and leave to rise in a warm place for about 15 minutes. Melt the fat and let it cool down.
Add 30 g sugar, vanillin sugar, salt, 1 egg and fat and knead with the kneading hooks of the hand mixer to a smooth dough. Cover and leave to rise for about 30 minutes. In the meantime bring 125 ml milk, 100 g sugar, cinnamon and cocoa to the boil, add hazelnuts and remove from the heat. Let it cool down a little bit and stir in 1 egg. Roll out the dough on a floured work surface to a rectangle (approx. 30x40 cm). Add the filling and spread evenly. Roll up from the long side. Use a sharp knife to cut off slices about 4 cm thick. Place slices close together in a well greased springform pan (26 cm Ø). Cover and leave to rise for another 20 minutes. Whisk the egg yolks and spread on the cake. Sprinkle 20 g hazelnut leaves on top.
Use a sharp knife to cut off slices about 4 cm thick. Place slices close together in a well greased springform pan (26 cm Ø). Cover and leave to rise for another 20 minutes. Whisk the egg yolks and spread on the cake. Sprinkle 20 g hazelnut leaves on top. Bake in the preheated oven (electric range: 200 °C/ convection oven 175 °C/ gas: level 3) for 35-40 minutes. Let them cool down. Warm up the jam and pass through a sieve. Remove cake from the tin. Spread the edge with the jam. Sprinkle 30 g hazelnut leaves on the edge. Serve dusted with icing sugar
Let them cool down. Warm up the jam and pass through a sieve. Remove cake from the tin. Spread the edge with the jam. Sprinkle 30 g hazelnut leaves on the edge. Serve dusted with icing sugar
Waiting time approx. 45 minutes