Tray size 30x40 cm covered with parchment paper, greased with butter. Grated chocolate and coffee mix and leave on low heat until chocolate is melted. Allow to cool. In a separate bowl whisk the egg yolks with sugar eggs until white set and thicken. Mix up the cold with chocolate, adding cognac. Whip until the air, but no dry foam, and a thin stream is added to the chocolate. The chocolate was poured into the tray and smoothed. The tray is placed in a preheated 170 C oven for no more than 15 minutes (the chocolate mixture is ready, if you do not stick to the knife stuck in it). Remove, cover with a damp cloth and leave in refrigerator for 1 hour. parchment paper size slightly larger than the tray dusted with cocoa. On it gently inverted tray and lift the parchment paper that was on the bottom. Cream mix with vanilla and chocolate smeared on. The roll is wound by the paper is lifted slightly at one end. If somewhere roll crack, the crack is filled with cocoa or with whipped cream.