How to cook
Mix the yoghurt and baking soda and let it become effervescent. Beat the eggs with the sugar, add the cocoa, vanilla, and beat the whole mixture with the yoghurt and baking soda. Add the flour and oil gradually and beat until homogeneous.
Pour the mixture into a baking form, pre-buttered and floured. Put the plain cocoa cake to bake for about 50 minutes in a preheated to 320°F (160 °C) oven. Optionally, add nuts and dried fruits as desired.