Marble cake with olive oil and yogurt. Simple and tastefull by G.CH-K

Preheat the oven at 350 F (180 C). Separate the eggs in two bowls. Put in one the whites and let aside.Then put at the other the yolks and the flour sifted together with all the ingredients except from the cocoa powder and the milk. Whisk them by hand or with stand mixer and add the milk until you get the consistency that you want (the mixture is thick but easy to whisk(not watery)). Meanwhile whisk the egg whites by hand or even better with an electric mixer to meringue (about 4 minutes in high spead). Then incorporate the meringue into the mixture slowly using a spatula. Separate in two and put in one half the cocoa powder and mix it. Put the half white mixture in the pan then all the dark one and on top the other half white. Take a butterknife and make circles. Bake for about 1 hour and 15 minutes. Let it cool completely and decorate it! Enjoy, G.H-K