Preheat the oven to 190C/375F/Gas 5. Grease and line five Swiss roll tins.
Beat the eggs and sugar in a large bowl until pale and tripled in volume.
Sieve the flour into the mixture and stir very gently until just combined.
Pour the mixture into the lined tins and bake in the oven for 10-12 minutes or until golden-brown all over.
Turn the sponges out and allow to cool a little on a wire rack. Peel off the greaseproof paper.
Spread the top of the sponge with jam then carefully roll up the sponge, starting with the short side, until you have a log shape.
Sit the log so that the seam is on the underside and dust with icing sugar.