Tray size 30x40 cm is smeared with butter and cover with parchment paper also greased with butter. Yolks of eggs broken with sugar and white set as to increase the volume three times. The walnuts mixed with baking powder and vanilla and add to the egg yolks. Egg whites are broken down into the air, but no dry foam and mixed with the egg yolks. Egg whites must be broken down into a dry container, in which there are no traces of fat. If used razbivachka, it should not touch the walls and bottom of the container. Egg white-yolk mixture is poured into a pan and smoothed. The tray is placed in a preheated 180 C oven for no more than 15 minutes (the walnut mixture is ready, if you do not stick to the knife stuck in it). Remove, cover with a damp cloth and leave to cool completely. parchment paper dusted with a thick layer of powdered sugar on it and gently inverted tray. Removed from the parchment paper, which was on the bottom. Cream mix of dense foam, finally add the cognac. The resulting cream is applied to the nut-cooked egg mixture, which is rolled up, the paper is lifted slightly at one end. If the roll is cracked, the cracks are filled with whipped cream.