Eggs are divided into yolks and whites. Yolks are broken with half the sugar until white. Egg whites are broken down into hard snow with a pinch of salt and half of the sugar. Melt the chocolate with the butter and vanilla. The mixture was allowed to cool and then added to the egg yolks. Stir least - as to be mixed and added to the car. After stirring, the egg white snow. Put it less stirring gently so as not to come out of the air mixture. The flour is sieved and mixed with the baking powder was then added a little to the egg mixture. All pour into greased and floured form or tray. Bake in a preheated 180C oven for 50 minutes, checking with a toothpick. Once baked the cake is removed and turned on a grid (I use the grill in the microwave). Standing 20 minutes in this way, then converted into a plate. Sprinkle with powdered sugar.