Cut the almonds in half lengthwise with a small knife. Coarsely grate the marzipan. Sift icing sugar and flour. Separate the egg. Put egg white, icing sugar mixture and marzipan in a bowl and knead with the dough hooks of the hand mixer to a smooth mixture.
Shape into small balls with slightly moist hands. Place on a baking tray lined with baking paper. Whisk egg yolk and milk. Brush the balls with it. Press 3 almond halves on each ball.
Bake in the preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: level 1) for 15-20 minutes. Let them cool down.