How to make
Beat the eggs. To them add the sugar and continue beating. Add the yoghurt, then the oil and finally the flour with baking powder.
Smear a cake form with butter. Pour in 1/2 of the mixture. Use a spoon to pour Nutella randomly on top. Cover with the rest of the mixture.
Bake this cake at 360°F (180 °C) for about 35-40 min. Let it cool, remove from the form and invert onto a plate.
I used a silicone form and didn't have to sprinkle it with flour.