For lining cake moulds, etc. with the sponge, bake in a flat, large oven tray, so you can easily cut it into strips. If you want a cake filled with jam, fruit or pastry cream, bake it in a smaller, round or square cake tin to make a higher cake.
Beat the eggs in a bowl with the sugar until they are pale, very thick and creamy. This will take quite a while. Add the sifted flour bit by bit, mixing in well after each addition. Add the salt and the vanilla, and whisk in to incorpora