4 yolks are broken down into sugar, add the flour, the oil, Schweppes and the walnuts. Mix well. Egg whites are broken down into snow and added with gentle stirring. Attention is less than the mixture, and thereto is added the chocolate. Half of the mixture was poured into a greased and sprinkled with flour cake pan. Pour the cocoa mixture, followed by the other half of the base mixture. Top ranks finely chopped Turkish delight. Bake in preheated moderate oven. Cool cake sprinkled with powdered sugar.