1 tsp vanilla essence
450ml warm strong black coffee
4 egg yolks
75g caster sugar
284 ml double cream
200g pack sponge fingers
Cocoa powder to dust
Put the mascarpone into a bowl with the vanilla essence.
Pour the coffee into a shallow dish.
In a large bowl, whisk the egg yolks and sugar together until pale and thick, then whisk in the mascarpone until smooth.
Whip the cream in another bowl into a stiff peak, then fold it into the mascarpone mixture.
Take half of the sponge fingers and dip each one at a time in the coffee mixture; arrange them over the base of a 2.4 liter shallow dish. Spread a layer of mascarpone mixture over the sponge fingers, then dip the remaining sponge fingers into the coffee and arrange on top. Finish with a top layer of mascarpone and a dusting of cocoa powder.
Cover and chill for at least 2 hours before serving.