Ingredients
Method
- Preheat oven to 200°C / 180°C fan / Gas 6. Grease and line a 33x23cm tin. Prepare a second sheet of parchment — dust generously with caster sugar. Set aside flat.
- Whisk egg yolks, sugar, vanilla, and salt 3–4 minutes until very pale, thick, and ribbon-like. Whisk egg whites in a separate bowl to stiff peaks.
- Sift flour over yolk mixture. Add boiling water. Fold gently 8–10 strokes. Add one-third of egg whites — fold to loosen. Add remaining whites in 2 additions — fold very gently until no white streaks remain.
- Pour into tin immediately — tilt gently to spread to corners. Bake 10–12 minutes until pale golden and springy.
- Turn immediately onto sugar-dusted parchment — peel away lining parchment. Trim short ends. Score a line 2cm from one short end. Roll up tightly from scored end using the parchment. Cool completely — 45 minutes.
- Unroll gently. Spread warmed jam to the edges. Spread whipped cream over jam. Re-roll firmly — seam underneath. Dust generously with icing sugar. Refrigerate 30 minutes. Slice thickly.
Notes
Roll the sponge immediately while hot — a cooled sponge has set flat and will crack.
The two-roll technique — roll hot without filling, cool, unroll, fill, re-roll — takes the pressure off.
Fold egg whites very gently — the air is the only leavening in this fatless sponge.
Boiling water gives a more pliable, more rollable sponge — do not omit.
Do not overbake — 10–12 minutes maximum. Overbaked sponge cracks during rolling.
Do not freeze — the cream filling does not survive and the sponge becomes soggy.
