Cut the almonds in half lengthwise with a small knife. Coarsely grate the marzipan. Pass the icing sugar and flour through a fine sieve. Separate the egg. Put egg white, icing sugar, flour and marzipan grater in a bowl. Knead with the dough hook of the hand mixer to a smooth mixture.
Form small balls with moistened hands. Place on a baking tray lined with baking paper. Whisk egg yolk and cream and 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 about 20 minutes. Let them cool down on a kitchen grid