How to make
Beat the eggs with the sugar until you get a foam. Mix the yoghurt with the baking soda and add it to the egg mixture.
Add all the remaining ingredients, excluding the cocoa. Stir until homogeneous.
Divide the resulting mixture into 2 parts. Add cocoa to one of them and stir again.
In an oiled and floured round baking dish, pour a little of 1 mixture, but not right in the middle of the dish, then pour on a little of the other in the middle of that one.
Make another circle of mixtures and continue until you've filled the baking dish and run out of mixtures.
Bake in a preheated 360°F (180 °C) oven for about 40 min.
Once it cools, sprinkle it evenly with powdered sugar.
