How to make
Separate the egg whites from the yolks. Beat the egg yolks into a fluffy cream with 1/2 of the butter, flour and 1 cup of milk. Put the remaining milk on the stove to boil it with sugar. While stirring constantly, add the yolk mixture to it and stir until it thickens. Then remove it from the heat and mix with the vanilla and remaining butter.
Allow the cream to cool and add the egg whites, beaten to hard snow with 2 tablespoons of sugar. In a suitable tray or pan place the first cake layer, lightly syrup it with the juice, but not too much, so it doesn't make the cake fall apart afterwards. Smear cream and put a few tablespoons of jam on.
Put the second cake layer on and repeat until you finish with a layer of cream. Top well with the other 2 egg whites, which you've beaten to snow with 2 tablespoons of sugar.
Let the cake cool for 2-3 hours before serving.