Grate marzipan. Sift 80 g icing sugar and 30 g flour over it. Add egg white. Knead to a smooth dough.
Colour half the dough red. Roll out the doughs separately between 2 lightly floured layers of baking paper to a thin rectangle (approx. 15 x 18 cm). Remove the upper paper in each case. Brush one dough sheet with water.
Carefully turn over the other sheet of dough using the paper. Put the double pastry sheet in a cool place for about 1 hour.
In the meantime boil the almonds briefly in water, then quench. Squeeze the seeds out of the skin and cut them in half lengthwise.
Preheat oven (electric cooker: 150 °C/circulating air: 125 °C/gas: see manufacturer). Pull paper from the dough sheet. Divide the plate into thirds lengthwise. Spread a thin layer of water on the surface. Place the third of the dough on top of each other.
Cut lengthwise into 3 strips (each approx. 2 x 15 cm). Cut each strip into pieces of approx. 1 cm. Place on a baking tray lined with baking paper. Bake in a hot oven for about 20 minutes. Take out and let cool down.
For the icing, stir lemon juice and 75 g icing sugar until smooth. Coat the Bethmännchen with the icing. Place the almond halves on top and press down gently. Let the icing dry.