Whip two egg whites in to a firm foam, the same consistence as shaving foam.
Mix the almond flour together with two hundred grams of icing sugar and the cinnamon in a bowl.
Add the almond mixture gently in the egg whites and stir very gently together. Add the citron juice and continue work the dough. If the dough is to sticky you can add some more almond flour. The dough should not stick to the bowl, if it does it is still too sticky.
Sprinkle a working bench with some icing sugar.
Roll out the dough on the bench, it should be approx 1 cm thick.
Make stars with a cookie form and place the stars on a baking paper.
Mix one egg white together with hundred grams of icing sugar in a bowl, and paint the stars with the frosting.
Let the bredeles rest in room temperature for 10 hours.
Preheat the oven at 240 degrees Celsius.
Place the bredeles in the middle of the oven for five minutes.
Take out the cookies from the oven and let them cool down on the oven grill in room temperature.