Break the eggs into a bowl and add sugar.
Beat them with an electric whisk.
Add the oil, water and lemon zest while mixing.
Add the sifted flour a little at a time, continuing to mix.
Add baking powder and keep mixing.
Evenly pour the batter in a 24-cm-diameter baking pan which you will have priorly greased with EVO oil and floured.
Bake in a preheated ventilated oven at 170°C for 40 minutes, or in a static oven at 180°C also for 40 minutes.
While the dough is in the oven, squeeze 100 ml of lemon juice and 100 ml of orange juice and put them in a pitcher.
Place sugar and cornstarch in a small saucepan then mix them.
Stir in the orange and lemon juice a little at a time.
Place the saucepan on the stove and keep stirring, until the cream is thick.
Once the cake is ready, let it cool.
Remove it from the pan and cut it in half.
Spread the lemon cream over the base, leveling it with a long-bladed knife.
Put the other disk on top and sprinkle some icing sugar.