First, blanch the almonds and let them cool. They must be completely cold before you use them.
Pour sugar and water into a pot and bring it to a boil.
Remove the pot from the heat when the sugar has completely dissolved in the water and let it cool down.
Place the cooled, blanched almonds in a blender and start the machine. It is necessary to stop a few times along the way to scrape the sides and bottom of the blender. Continue until the almonds are ground into a very fine almond flour.
Gradually add the cooled sugar syrup into the blender while the blender is running. The almond flour and sugar syrup will begin to combine, and your marzipan is ready when it is still moist but no longer sticky.