Beat the eggs and sugar until whitened with a mixer. Add the yoghurt and continue beating. Add the flour, mixed with the baking powder, and continue stirring with a wooden spoon.
Add the oil and raisins, which you've soaked in alcohol beforehand.
Roll the candied orange peels in flour and put them in the mixture. Grate a little lemon rind and stir.
Set aside 1 cup of the mixture. To it, add 1 tbsp cocoa and stir. In a buttered and sprinkled with cocoa form, pour the white mixture and then the brown one on top.
Bake in a preheated 356°F (180 °C) oven about 40 min. I didn't have powdered sugar for sprinkling, so I used melted chocolate to smear it once it cooled.