4 free-range eggs, separated
1 tsp vanilla extract
125g/4½oz caster sugar
115g/4oz plain flour
1 tbsp instant espresso coffee powder
400ml/14fl oz double cream
4 tbsp vodka
4 tbsp coffee liqueur
60g/2oz amaretti biscuits
20g/¾oz cocoa powder
Preheat the oven to 190C/170C Fan/Gas 5 and line three 18cm/7in cake tins with greaseproof paper.
In a large bowl, whisk the egg yolks, vanilla and half the sugar together for 5 minutes, or until very pale.
In a large, glass bowl, whisk the egg whites using an electric whisk, slowly adding the remaining sugar and the salt until they hold soft peaks. Gently fold the whites into the yolks. Sift and fold in the flour.
Fill the tins equally with the mixture and bake for 15 minutes, or until firm to the touch and golden-brown.
Carefully remove the cakes from their tins, discard the paper and leave to cool on a wire rack.
Mix the espresso powder with 200ml/7fl oz boiling water, leave to cool, then brush both sides of the sponge with the coffee.
In a medium bowl, using a handheld whisk, mix a little of the cream with the mascarpone until smooth. Add the remaining cream, vodka and coffee liqueur, whisking until slightly stiffened.
Place the amaretti biscuits with half the cocoa powder in a food processor and blend to make a crumb.
To serve, place a layer of sponge in an 18cm/7in glass trifle bowl, spread with a half the cream mixture and top with half the amaretti-cocoa crumbs. Repeat this process with a second layer of sponge, cream and crumbs. Finish with the final sponge and a dusting of cocoa powder.