Soda stir in milk until effervescent and pour into a deep bowl. Add sugar and mix with a mixer a smooth mixture. Gradually add flour. After him, the oil trickle. Mix everything well. Greased pan with sunflower oil, dusted with flour and sent down one part (about half) of the mixture inside. In the other part add cocoa and Beat well. Pour this part in the pan and spoon shuffle carefully. Bake in a moderate oven. The finished cake waiting for it to cool and spread top with jam or chocolate spread.