Cream butter, sugar, vanillin sugar and salt for about 10 minutes with the whisk of the hand mixer. Stir in eggs bit by bit. Stir in cream yoghurt. Mix flour, baking powder and sauce powder and stir briefly into the egg-sugar mixture. Spread 1/3 of the dough into a greased box form (30 cm length/ 2 litres capacity).
Spread half of the caramel sweets on top. Spread 1/3 of the dough mixture on top. Spread the rest of the caramel sweets on top and cover with the remaining dough. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 50-60 minutes. Remove the cake from the oven and let it rest in the mould for 5 minutes. Turn out of the mould and let it cool down. Chop dark and light chocolate coating. Melt the dark chocolate coating over a hot water bath and let it run evenly over the cake. Chill the cake for 20 minutes. Melt whole milk couverture.
Turn out of the mould and let it cool down. Chop dark and light chocolate coating. Melt the dark chocolate coating over a hot water bath and let it run evenly over the cake. Chill the cake for 20 minutes. Melt whole milk couverture. Run over the cake so that the dark chocolate coating is still visible. Let the cake dry and cut into slices
waiting time approx. 1 3/4 hours