• 240 ml strong espresso, cooled
• 30 g cocoa powder, plus extra for dusting
• 5 ml vanilla extract
• 4 pasteurised egg yolks
• 100 g caster sugar
• Pinch of fine salt
• 500 g mascarpone, chilled
• 300 ml double cream, well chilled
• 300 g crisp ladyfingers (savoiardi)
• 30–60 ml purified water (to soften espresso bitterness if needed)
• Optional: 30–45 ml Marsala, dark rum or coffee liqueur

1. Flavour base. Whisk espresso, cocoa and vanilla in a shallow bowl until smooth. If the mix tastes too harsh, whisk in 30–60 ml purified water. Stir in alcohol if using.
2. Yolks & sugar. Beat yolks with sugar until very pale and thick, 4–5 minutes. Beat in the salt.
3. Mascarpone cream. Beat in mascarpone just to smooth. Add cold double cream and whisk to soft peaks.
4. Layer. Dip each ladyfinger briefly (1–2 seconds) in the espresso mixture; arrange in a snug layer in a 20×30 cm dish. Spread over half the mascarpone cream. Dust lightly with cocoa. Repeat with remaining biscuits and cream.
5. Chill & serve. Cover and chill at least 2 hours (overnight is best). Dust with cocoa before serving.

Make-ahead: Keeps covered in the fridge up to 4 days.