For the biscuits, mix flour, baking soda and 1 teaspoon ginger. Melt 25 g sugar, 25 g butter and syrup in a small pot. Add to the flour mixture with the egg yolk. Mix to a smooth dough with the dough hooks of the hand mixer.
Roll out the dough on a floured work surface approx. 4 mm thin and cut out approx. 16 stars (approx. 5 cm Ø). Bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 15 minutes until golden brown.
Let it cool down on a cake rack.
In the meantime, grease 8 ovenproof moulds (approx. 200 ml each). Finely grate 30 g chocolate. Sprinkle the moulds with the chocolate. Coarsely chop the remaining chocolate. Melt in a bowl over a warm water bath with the remaining butter, cinnamon and 1 tsp. ginger.
Remove the bowl from the water bath and let it cool down for about 5 minutes. Separate the eggs. Beat the egg whites with the whisks of the hand mixer until stiff, adding 100 g sugar. Stir the egg yolks individually into the chocolate mixture.
Carefully fold in the egg white and distribute into the prepared moulds. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 12 minutes. Dust with icing sugar and decorate with cookies.
Serve immediately.