Beat 4 eggs to a froth, add 1 Cup of sugar and continue to beat until white.
Add 1 tsp baking powder, 1/2 bag of vanilla sugar, 4 tbsp flour.
Separately, heat 160 gr. butter and 100 gr. dark chocolate in a water bath, cool.
Mix the two mixtures, add the chopped walnuts and mix.
Cover the form with parchment and pour out the dough. Bake at 180 deg. 25-30 min.