Step 1

Grease and line the base and sides of a 7cm-deep, 10 x 20cm (base measurement) loaf pan with baking paper, allowing long sides to overhang.

Step 2

Place boiling water in a small heatproof bowl and sprinkle with the gelatine. Stir to combine. Place bowl in a larger heatproof bowl and add enough boiling water to come halfway up the side of small bowl. Set aside, stirring occasionally, for 5 minutes or until gelatine dissolves.

Step 3

Use electric beaters to beat the egg yolks, sugar and vanilla in a large bowl until pale and creamy. Add the mascarpone and 375ml (1½ cups) cream. Beat until soft peaks form. Beat in gelatine mixture until combined.

Step 4

Pour the espresso martini into a shallow bowl. Place ½ cup mascarpone mixture into base of prepared pan. Smooth the surface. Working with 6 biscuits, 1 at a time, dip both sides into espresso martini. Place biscuits lengthways on top of mascarpone layer, trimming to fit if necessary. Top with 1 cup of the mascarpone mixture. Smooth the surface. Repeat with another 6 biscuits and 1 cup of the mascarpone mixture and Smooth the surface. Working with 8 biscuits, 1 at a time, dip both sides into the espresso martini. Place biscuits on top of mascarpone layer. Top with the remaining mascarpone mixture. Smooth the surface. Repeat dipping with remaining biscuits to make a final biscuit layer, pressing down gently. Cover with the overhanging paper and place in the fridge overnight to set.

Step 5

To make the coffee syrup, combine coffee, sugar and vanilla in a small saucepan over low heat. Stir for 1-2 minutes or until sugar dissolves. Increase heat to medium. Bring to a simmer. Cook, without stirring, for 5 minutes or until the syrup thickens slightly. Remove from heat. Set aside to cool completely.

Step 6

Use electric beaters to beat remaining cream and extra sugar in a bowl until firm peaks form. Transfer to a piping bag fitted with a 1cm plain nozzle.

Step 7

Turn out tiramisu onto a platter, gently tugging paper, if necessary, to release. Pipe peaks of the cream over the top of the tiramisu. Dust with cocoa powder. Serve with espresso syrup.