Preheat your oven to 180° C or 355° F and line a sheet pan with buttered parchment paper.
Crack the eggs, separating the whites and yolks.
Mix the yolks with the sugar until they whiten.
In a bowl, add a pinch of salt to the egg whites and beat until they form stiff peaks.
Add half the egg whites to the yolk mixture, and mix well. Then gently fold in the second half of the egg whites being careful not to over-mix. Finally, slowly incorporate the sifted flour.
Using a large icing bag with a smooth tip, pipe the dough on the buttered paper in the desired shape, traditionally a long, oval shape. You can also pipe a round shape to make the base of a dessert or a round cookie instead.
Put your cookies in the oven at 180° C or 355° F for ten to fifteen minutes.
Dust your cookies with powdered sugar before or after baking. Professional bakers generally do it before.