(Original in German: here)
200g dark chocolate
5 tablespoons sugar
2 tablespoons flour
(2 tablespoons Kirsch, optional)
Preheat the oven to 160°C, line a 26cm diameter springform pan with parchment paper and grease the rim with butter.
Break the chocolate into pieces and put into a small saucepan together with the Kirsch and the butter. Melt over low heat. Let cool slightly.
In a bowl, beat the eggs together with the sugar for about 5 minutes until you got a pale and thick batter. Add the melted chocolate. Then, add the flour. Pour your batter into the prepared springform pan and smooth down with a ladle. Spread the raspberries on your batter (they can sink down during the baking).
Bake for about 35 minutes. This cake gets better after letting it cool down thoroughly and chilling it in the fridge for a bit. The texture will be wonderfully smooth.
(I halved the recipe above and made a small cake of 18cm diameter)