Line and grease an 18 x 28 cm/7 x 11 inch Swiss roll
tin.
Whisk the eggs and sugar in a mixing bowl over
a saucepan of hot water until thick enough to leave
a trail. (Hot water is unnecessary if you are using
an electric whisk.)
Fold in the flour and water,
then turn into the prepared Swiss roll tin.
Bake in
a preheated oven,
200°C
(400°F), Gas Mark 6, for
8-10
minutes, until the cake springs back when lightly
pressed.
Turn out the roll on to a sheet of
greaseproof paper dredged with sugar. Peel off the
lining paper and trim the
edges.
Spread
lightly with
the jam and roll up quickly.
Hold in position for a
few minutes, then transfer to a wire rack to cool.
Dredge with caster sugar before serving.