Preheat oven to 180C non-fan forced.

Prepare large rose gold baking tray (38 x 26cm) with baking paper. (lightly grease tray and scrunch up paper, then press it in, ensuring it comes just up the sides, but no further)

Place a bowl on the lid of the Thermomix and weigh in flour, baking powder and salt.

Set aside and have a sieve ready.

Insert butterfly and add eggs and sugar to the bowl.

Set machine to 6 min/37/sp 3.5/MC on.

Then set to 6 min/3.5 no heat and no MC.

Sieve flour mix into egg mixture.

Mix 3 sec/sp 3.

Remove butterfly and use spatula to gently stir in any remaining flour.

Pour into tray and bake 14 - 16 minutes.

Meanwhile, lay a tea towel on the bench and place another sheet of baking paper on top - larger than the cake. Sprinkle with the extra caster sugar.

Carefully turn out cooked cake onto baking paper and remove the paper from the top of the cake.

Make a slice 2 cm in from one short edge without cutting all the way through - this makes it easier to roll up.

Roll up, using the tea towel and enclosing the sugared paper.

Cool, then carefully unroll and spread with jam. re-roll without the baking paper.

Slice with a serrated knife.

Freezes well.