Rolled sponge cake with raspberry jam

Separate the eggs, yolks in one bowl and whites in another.

Add 80 g white sugar to the egg yolks and mix until they whiten.

Mix 40 g corn starch into the yolks to a smooth compound.

Whisk the egg whites with a little salt to a firm meringue, using a hand mixer.

Pour the meringue over the yolk mixture and fold it in with a whisk in two additions, half first, waiting for it to incorporate before the rest.

Pour the mixture onto a lined baking tray and level it flat with a spatula so it is the same depth everywhere.

Preheat the oven; the setting given is 250-220 degrees Celsius.

Bake 10 minutes.

Sprinkle flour over a sheet of baking paper.

Turn the hot sponge upside down onto the floured paper and peel away the paper it was baked on.

Spread a thin layer of raspberry jam over the sponge while it is still hot.

Roll the sponge up immediately, while hot.

Move the roll to a tray and coat it all over with icing sugar.

Rest and cool 30 minutes, then trim the untidy end and slice.