Melt the 150 g chocolate in a water bath and allow to cool slightly. Mix the liquid chocolate with the butter until frothy. Add powdered sugar and egg yolks, stirring further. Mix the flour with the baking powder and stir into the mixture. Beat the egg whites into firm snow while pouring in the 30 g of sugar. Carefully fold the egg whites into the dough. Put the dough in a greased springform pan.
Bake in a preheated oven at 180 ° C for about 50-55 minutes.
After cooling, cut the cake once (if it is very high, you can divide it twice) and coat the bottom with apricot jam. Put the lid on. Finally, cover the entire Sachertorte with melted couverture.
Tip: Lasts forever if you wrap the cake tightly in aluminum foil. The longer the jam soaks into the dough, the juicier it will be.