Roughly chop the chocolate. Melt the butter and chocolate in a small saucepan over low heat while stirring. Remove from the heat and allow to cool slightly. In the meantime, roughly chop the walnuts, almonds and Brazil nuts.
Mix eggs, sugar, vanillin sugar and salt with the whisk of the hand mixer until thick and creamy. Pour the melted chocolate-fat mixture into a large mixing bowl. Stir in the egg-sugar mixture.
Add flour and baking powder and stir in. Fold in nuts and almonds and put the dough on a well greased fat pan. Smooth and bake in a preheated oven (electric: 175 °C/ gas: level 2) for approx. 25 minutes.
Take it out of the oven. Place on a grid and let it cool down. Cover as desired with stencils (star shape) and dust thickly with icing sugar. Cut into 60 pieces. Arrange in paper cups as desired.