Heat the oven to 180°C/fan160°C/gas 4. Grease a 20cm loose-bottomed cake tin and line the base with baking paper.
Whisk the eggs and sugar with an electric hand mixer for 3-5 minutes until light, mousse-like and doubled in size.
WHISK UNTIL RIBBON STAGE is reached. To test for this, turn off the mixer, lift out the whisks and let the mixture fall back in. It should fall in a ribbon-like trail and hold itself there for a few seconds before sinking back in. If not, whisk more, then repeat.
Sift the flour over the cake mixture with a pinch of salt. Fold in as above, being as light and gentle as possible, until no traces of flour are visible.
Pour into lined greased tin, bake for approx. 30/35 mins – 150`c until springy
Slice in half when cooled and fill with fresh whipped cream and jam.