Beat the eggs with the sugar, oil, yoghurt, vanilla and lemon zest.
Add the flour, sifted with the baking powder, and the semolina. Pour the mixture into a buttered and floured oven dish and bake at 356°F (180 °C) for 25-30 min.
To make the syrup, mix the water and sugar in a pot. Put it to boil and once it does, wait 5 min. before adding the lemon juice. Take it off the stove.
Cut the cold sponge cake into pieces and pour the cold syrup over it.