Marbled sponge cake

Instructions

1. Grease the baking tin with butter or with a release spray.

2. Put the eggs and sugar in a bowl and beat them for 5 minutes with the wire whisk.

3. While continuing to whisk, add the yoghurt and whisk for a few seconds.

4. Add the oil in the same way and whisk again for 5 seconds.

5. Add the sifted flour and the baking powder. Beat for just 1 minute. Finish integrating the dough with a spatula.

6. Separate half of the dough into another bowl, add 2 tablespoons of cocoa powder with the help of a sieve, so that there are no cocoa lumps, and stir with a spatula. To this mixture, the one with cocoa, add 2 tablespoons of milk and stir.

7. Add the vanilla extract to the other half of the batter.

8. Pour the two doughs at the same time into the mould, mixing them together. Stick a skewer stick in until it touches the bottom of the mould and then make "eses" all over the dough. Put the spoonful of sugar on top.

9. Set the air fryer for 25 minutes at 165 degrees. Finish with 3 more minutes at 160 degrees. The time depends on the material of your mould, so you will have to do your own tests.

10. Take it out and as soon as it has cooled, unmould it and place it on a wire rack.