How to make
Beat the yolks with the sugar and yoghurt, add the baking soda and oil. Pour in the vanilla and flour, stir very well, divide the mixture into 2, put the cocoa in 1 of them and stir well. Smear the tray with oil and a little flour.
Start arranging, pouring 1-2 tbsp of the cocoa mixture in the middle, then of the vanilla one and so on until you run out. Bake until golden, smear with strawberry jam.
Beat the egg whites with sugar to snow and smear the cake with it. You can pull them upward for a nicer effect. Sprinkle with walnuts and return to the oven briefly.
