Beat the sugar and eggs to produce a creamy mixture. Add the cocoa, baking powder, cooking oil and stir continuously.
Put the baking soda in the yogurt and after several minutes, add it to the mixture. Add the flour. Beat well.
Pour the batter into a greased cake form. Bake at 392°F (200 °C) for 20 - 30 minutes (depending on the oven). When it is ready, let it cool for a few hours in the refrigerator.
Serve with a chilled yogurt of your choice :) Enjoy!