Finely dice 50 g marzipan. Put flour, almonds, sugar, marzipan, salt, bitter almond oil and egg yolk in a bowl. Add butter in pieces. Knead to a smooth dough with the dough hooks of the hand mixer. Form into a ball with your hands, wrap in foil and chill for about 1 hour. Roll and shape small pieces of dough into croissants. Place on 2 baking trays lined with baking paper.
Bake the trays one after the other in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 10 minutes. Let them cool down on a cake rack. Coarsely chop the chocolate coating and melt on a hot water bath. Dip a tip of each crescent into it and put it back on a cake rack. Roll out 30 g marzipan between 2 layers of foil, cut out small stars. Decorate croissant with marzipan and small sugar stars, let dry for about 1 hour. Dust with cocoa