Mix flour, cocoa powder, icing sugar and salt. Add egg yolk and butter in flakes. Knead first with the dough hooks of the hand mixer, then with your hands to a smooth dough. Cover and chill for about 1 hour. Sort the sweets by colour and crush them separately in the universal chopper. Roll out the dough on a floured work surface. Cut out fir trees (7 x 4.5 cm) and stars (8.5 cm Ø).
Cut out the middle of the Christmas trees with a small cookie cutter (4.5 x 2.5 cm) and the middle of the stars with a small star (2.5 cm). The resulting frame should be at least 1 cm wide. Using a pallet, place the biscuits on a baking tray lined with baking paper. Make 1 hole in each cookie in a suitable place with the back of a pointed brush. Place some candy crumbs in the middle of each cookie and bake in the preheated oven In the preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: level 1) for 8-10 minutes one after the other. Remove the cookies and let them cool down. Carefully pierce the cookie holes again with a toothpick, thread a ribbon through them and hang them up
1 hour waiting time