Espresso semifreddo sandwiches
- Place the coffee, water and liqueur in a bowl and stir until the coffee is dissolved. Set aside to cool.
- Place the eggs, extra yolks, vanilla and sugar in a heatproof bowl. Place over a saucepan of simmering water and, using a hand-held electric mixer, beat for 6-8 minutes or until thick and pale.
- Remove from the heat and allow to cool slightly. Whisk the cream until stiff peaks form. Gently fold cream and coffee mixture through the egg mixture until well combined.
- Pour into a 2 litre-capacity metal tin and freeze for 6 hours or overnight.
- Sandwich semifreddo between biscuits to serve.