Tiramisu cheesecake

Invert base of a 20cm springform pan. Grease and line base and side of pan with baking paper.

To make crust, process biscotti in a food processor until finely crushed. Add butter and process until combined. Press over the base of the prepared pan. Refrigerate.

To make filling, sprinkle gelatine over ¼ cup water in a small, heatproof jug. Sit jug in a small saucepan of simmering water. Stir until gelatine is dissolved. Remove. Cool slightly.

Beat the cream cheese and icing sugar mixture in a large bowl of an electric mixer until smooth. Add mascarpone, vanilla and combined liqueur and instant coffee granules. Beat until just combined. Beat in the gelatine mixture. 

Beat cream in a small bowl of an electric mixer until soft peaks form. Gently fold into cream cheese mixture. Spoon into the pan over crust. Smooth over top. Refrigerate, covered, overnight, or until set.

To decorate, spoon dollops of extra whipped cream around the edge of the cheesecake. Dust with sifted cocoa if desired.