How to make
Start with the egg custard, it must be chilled. In a bowl, beat the egg and sugar with a fork, add the flour and vanilla, mix.
Gradually pour the cold milk to them, stirring continuously, until a smooth, uniform mixture. Pour the mixture into a saucepan with a thick bottom and cook over moderate heat until thickened.
Transfer the custard to a glass bowl, cover with cling film and set aside to cool.
During this time, prepare the base. In a bowl, beat the eggs with the sugar using a mixer until fluffy.
Add the oil, vanilla, fresh milk and mix briefly again.
Add the sifted flour mixed with the baking powder and mix with a spatula.
Grease a 12x14″ (30x35 cm) rectangular cake tin with a little oil, flour it and pour the mixture into it evenly.
Pour the cooled cream on the base and smooth.
Place the tray in an oven preheated to 340°F (170°C) and bake for about 30 minutes or test with a dry toothpick.
After the cake has cooled, sprinkle with powdered sugar, serve!
The custard cake is ready.
