Place the eggs, the butter and the yogurt on the room temperature.

Preheat the oven to 180º and position a rack in the centre of the oven. For a better cake texture place another baking tray filled with water, on the bottom of the oven. The cake will be more fluffy.

Mix the soft butter with the sugar in a food processor (high speed) just until the sugar gets dissolved. Add the eggs gradually and mix again on low speed. Add the yogurt, lemon juice, zest, the flour gradually, the salt, the baking powder, pulse until combined. If the mix its too thick just add some more yogurt and a little bit of the lemon juice, if its too watery just add more flour.

Grease a small rectangular pan and place the mix. Bake for around an hour without opening the oven. Any thin skewer or knife can be used as a cake tester. Insert it into the centre of the cake, it should come out clean.