Pour the water into a small pot, add the sugar and stir until it is fully dissolved. Remove the boiled syrup from the heat and allow it to cool. Add half the crushed almonds to it. Whisk the egg white into snow and also add it to the sugar syrup. Heat the mixture a little once again, stirring constantly.
Remove the mixture from the heat and let it cool to 71.6°F (22 °C). Gradually and while stirring continuously, add the flour. Once you have added all of the flour, you need to get a soft dough, that you then knead for at least 10 more minutes.
Smear the tray with oil and lightly flour it. With a spoon or pastry syringe, shape small pastry circles and put half an almond in the center of each. Bake the cookies in a low oven at 284°F (140 °C) for about 40 minutes.
Allow to cool at room temperature and smear with the boiled syrup. Wait for the glaze to dry and serve.