Line two baking trays with baking paper. Cut toffee candies into 3 pieces each. Mix 250 g flour, cocoa, baking powder, sugar, 1 pinch of salt, butter in pieces, egg and liqueur first with the dough hooks of the hand mixer, then briefly knead until smooth with your hands.
Form approx. 36 balls from the dough with lightly floured hands and place them on the baking trays. Press the balls a little flatter (approx. 4 cm Ø) and press a hollow in the middle of each ball using a wooden spoon handle (approx. 1 cm Ø).
Bake one after the other in the preheated oven (electric oven: 200 °C/circulating air: 175 °C/gas: level 3) for about 11 minutes. Take out and put 1 piece of toffee candy each into the hollows. Bake the biscuits at the same temperature for about 6 minutes.
Approx. 1⁄2 Allow to cool down for a minute. If the toffee mass does not stick well to the biscuits, press down carefully. Cool down completely.
Break the chocolate into pieces, melt in a hot water bath with white fat. Leave to cool for about 15 minutes. Cover the biscuits with the chocolate icing. Let them dry. Decorate with gold leaf just before the icing takes effect.