Break chocolate into pieces. Melt with the butter in a hot water bath. Let it cool down a little. Grease a box mould (approx. 25 cm long; approx. 1.8 l capacity) and dust with flour.
Preheat oven (electric cooker: 175°C/circulating air: 150°C/gas: level 2). Beat ##eggs## and 150 g sugar with the whisks of the mixer for 6-8 minutes until foamy. Stir the liquid chocolate mixture into the egg cream.
Mix flour, baking powder and baking soda and briefly stir in alternately with the milk.
Fill the dough into the box form and smooth it down. Bake in a hot oven for 50-60 minutes (see tip). Remove the cake from the oven, let it rest on a cake rack for about 10 minutes, then turn out of the tin.
Prick warm cake several times with a wooden skewer.
Caramelise 100 g sugar immediately. Add ##nuts## and ##cream##, bring to the boil and simmer until the caramel has dissolved. Stir in 1 pinch of salt. Spread the liquid caramel over the warm cake.
Again, prick the cake several times so that the caramel flows into the holes. Let it cool down.