Beat egg yolks with sugar until frothy, add oil and water. Stir in the flour and cocoa. Beat egg whites with salt until very stiff and fold in carefully. Spread on a greased sheet and bake in the oven preheated to approx. 200 ° for 10-15 minutes.
Let cool down, brush with chocolate icing. The amount is enough for 2/3 baking sheet, then the dough is not too thin.