Method

• 1.
  Preheat oven to 160°C/140°C fan-forced. Grease a 22cm springform pan. Place 2 tbs coffee powder and shortbread in a food processor and whiz to crush. Melt 150g butter in a small saucepan and add to processor. Whiz to combine, then evenly press into the base and side of prepared pan.
• 2.
  Place remaining 1 tbs coffee and 50g butter, chocolate and condensed milk in a microwave-safe bowl and cook on high for 1 minute. Remove and stir until melted. Cool to room temperature.

• 3.
  In a stand mixer fitted with the whisk attachment, whisk cream cheese and icing sugar until smooth. Gradually add chocolate mixture, whisking constantly until smooth. Pour over base.
• 4.
  Place in oven and bake for 1 hour, or until just set with a gentle wobble in the centre. Turn off oven and cool completely in oven, then chill for 3 hours, or until firm and set.
• 5.
  To make the chocolate mousse, melt chocolate in a heatproof bowl set over a saucepan of gently simmering water (don't let base of bowl touch the water). Stir occasionally until melted and smooth. Cool slightly, then beat in the egg yolks (mixture may look seized at this stage, but it will come back together when you add the cream). Set aside to cool to room temperature, then in 2 batches, beat in half the whipped cream. Pour mousse over cheesecake, then chill for 4 hours, or until firm and set.
• 6.
  To serve, top with remaining whipped cream and dust with cocoa.