Prep time: 20 minutes, plus chilling.

Measure the mascarpone and about 50ml (2fl oz) of the cream into a large bowl, whisking until smooth. Slowly add the remaining cream and whisk again into soft peaks, being careful not to over-mix or it will be too thick. Fold in the vanilla extract and icing sugar.

Meanwhile, in a separate bowl, combine the coffee and brandy.

Break six of the sponge fingers in half and dip into the coffee and brandy mixture (see note). Arrange the soaked sponge fingers in the base of the tumblers. Spoon half of the cream mixture on top and half of the grated chocolate.

Break the remaining sponge fingers and soak in the coffee and brandy. Place on the cream layer, then spoon the remaining cream mixture on top, levelling neatly.

Chill for a few hours, if possible, then sprinkle with the remaining chocolate before serving at room temperature.

Cook's Notes: 

• If you can’t find sponge fingers, use trifle sponges or slices of sponge cake instead, though they are less robust once dipped, so take care when assembling.

• Give the sponge fingers a really good dunking in the coffee and brandy. There’s plenty to go around and, ideally, you want them to absorb all the flavour and add moisture to the dish.
 

Prepare Ahead: make up to 8 hours ahead and store in the fridge.

Not suitable for freezing.