In saucepan put the butter, pour the wine, pour the sugar and cocoa. Add 1 tbsp water and heat. When the butter is melted and the first bubbles appear, the court withdrew from the heat. The yolks of the eggs were removed and added to the cocoa mixture. Pour the flour and baking powder, stirring continuously. Once the mixture take the flour, add the beaten egg whites and in large pieces ground walnuts. Pour the mixture into cake pan and bake in a preheated to a temperature of 160-180 C oven until browned.