Adapted from the wonderful kitchen of Dr. Ola.
1 cup powdered sugar
4 cups ground almonds
1 tsp cinnamon
With an electrical mixer, beat the egg whites till stiff.
Start adding the powdered sugar gradually while folding with a spoon.
From this mixture, remove 4 tablespoons egg whites & keep them to cover the cookies at the end (keep them tightly covered, so as to not harden)
Do Not add sugar before the egg whites are stiff ,otherwise you will never get stiff eggs.
Add cinnamon & ground almonds & start mixing with hands till you have a a nice spreadable dough.
Spread some powdered sugar on your rolling surface & roll out the dough around 0.5 cm thick & cut into stars.
Cover every star with the egg whites with the back of a spoon.
Bake in preheated oven for 10-12 minutes (take care, the egg white color should not change).