Beat the yolks for the layers and gradually add the sugar and beat until whitened. Add the starches, pre-mixed with the baking powder. Finally, add the vanilla and beaten egg whites. Pour the mixture into greased and lightly floured oven dish, stir well and bake in a moderate oven until ready.
Divide the baked cake layer into 2 layers. Smear them with a syrup made from the boiled together water and sugar.
For the cream, beat the egg yolks and whites separately. Put the milk and sugar to boil. Dissolve the starch and flour in the water and once dissolved, add them to the yolks while continuously beating.
Pour this mixture into the milk and beat with a mixer. Pour in the vanilla and lemon zest and stir with a whisk until the cream thickens nicely. Allow it to cool and then mix in the beaten egg whites.
Stick the soaked cake layers together with this cream. Smear the cake generously with cream on top and make decorations as desired.