Step: 1/12

Preheat the oven to 220°C (200°C fan, gas 7). Separate the eggs and place the egg yolks in a mixing bowl.

Step: 2/12

Add 4 tbsp warm water and two-thirds of the sugar.

Step: 3/12

Blitz with a hand blender until pale and creamy.

Step: 4/12

Whisk the egg whites with the salt, gradually adding the remaining sugar. Whisk until stiff and glossy.

Step: 5/12

Place the beaten white eggs onto the egg yolk mixture and fold in. Sieve in the flour and cornflour.

Step: 6/12

Carefully fold in with the spatula.

Step: 7/12

Pour the mixture onto a baking sheet (30 x 40cm) lined with baking paper. Spread out evenly and bake for 10-12 minutes on the middle shelf of the oven until golden and springy.

Step: 8/12

Sprinkle a large tea towel with sugar. Carefully turn out the sponge, lightly sprinkle the baking paper with cold water and carefully peel away from the sponge.

Step: 9/12

Immediately roll up the sponge base tightly, using the tea towel to help, and leave to cool, seam side down.

Step: 10/12

Carefully unroll the cooled sponge roll. Add 5-6 tbsp of jam and spread out evenly with a spatula.

Step: 11/12

Whip the cream until stiff. Fold in the remaining jam and spread the cream over the sponge.

Step: 12/12

Carefully re-roll the sponge using the cloth. Chill for at least 3 hours. Serve with icing sugar.