Beat the lard with fat, sugar and vanillin sugar until foamy. Mix flour with salt of hartshorn and knead in. Remove one half of the dough and knead with cocoa. Chill both doughs overnight.
Form 45 balls from each dough and place them on baking trays lined with baking paper. Press the balls in with your finger and place them back on the baking tray with the curvature upwards. Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for 10 to 15 minutes.
Makes about 90 pieces.