Preheat the oven to 190°C/375°F/Gas mark 5.
Lightly grease a shallow 30 x
25cm/12 x 10in
Swiss roll tin and line the base with baking
parchment, extending over the two long sides.
Sift the flour 3 times on to baking parchment.
Beat the eggs with an electric beater in a
small bowl for 5 minutes, or until thick and
pale.
Add 100g/4oz sugar gradually, beating
constantly until the mixture is pale and glossy.
Transfer to a large bowl. Using a metal spoon,
quickly fold in the flour.
Spread into the tin
and smooth the surface. Bake for 10 to 12
minutes, or until lightly golden and springy to
touch.
Place a clean tea towel on a work
surface, cover with baking parchment, then dust
with the remaining caster sugar. When the cake
is cooked, turn it out immediately on to the
sugar.
Using
the tea towel as a guide, carefully roll the
cake up from the short side, with the paper.
Stand the rolled cake on a wire rack for 5
minutes, then carefully unroll and allow the
cake to cool to room temperature.
Spread with
the jam and re-roll. Trim the ends with a knife
and serve sliced.