Beat the soft lard, butter, sugar and vanillin sugar with the whisk of a hand mixer until foamy. Knead in the flour and ammonium bicarbonate of hartshorn. Halve the dough and knead the cocoa under one half. Wrap dough in foil and put in a cool place for about 3 hours. Form walnut-sized balls from the dough, place them on 2 baking trays lined with baking paper and press them slightly flat with a teaspoon. Bake one after the other in a preheated oven (electric: 200 °C/ gas: level 3) for about 15 minutes. Results in approx. 80 pieces