Preheat the oven at 180 degrees Celsius.
With an electrical mixer whip the egg whites to a hard foam.
Continue to whip while adding the sugar and vanilla sugar and make a shiny foam.
Stir gently while adding the flour, almond flour and the salt.
Place a baking paper on a baking sheet.
Make small balls and place them on the baking paper.
Place the baking sheet in the oven for approx. 15 minutes. Take out the cookies and let them cool down before serving them.