Tiramisu

• 300ml strong espresso, cooled
• 2 tbsp Marsala or dark rum (optional)
• 4 very fresh eggs, separated
• 100g caster sugar
• 500g mascarpone
• About 250g savoiardi (ladyfingers)
• Cocoa powder, for dusting

Whisk the yolks and sugar with an electric whisk until pale, thick and doubled in volume.

Beat in the mascarpone until smooth. Don't overbeat or it turns grainy.

In a clean bowl, whisk the whites to stiff peaks, then fold them into the mascarpone in three goes, keeping in as much air as you can.

Add the Marsala to the coffee. Dip each biscuit for 1–2 seconds a side and lay them in a 20 × 30cm dish. Spread over half the cream, then repeat the layers.

Cover and chill so the layers set. Overnight is even better.

Sift over a thick layer of cocoa just before serving.