Beat egg yolks long and hard, preferably with an electric mixer, dry thoroughly, then beat egg whites until they hold a soft shape.
Add sugar, a little at a time, and continue beating until mixture stands in peaks.
Fold into yolks gently, then sift flour and salt over the top and fold in, then add the vanilla.
Shape into thin fingers with a spoon or decorating tube on a cooky sheet lined with brown paper.
Bake in a preheated 350° oven for 10 to 12 minutes.
Cool on a cake rack and sprinkle with a little confectioners' sugar.