Espresso martini cheesecake

Method

1. Whizz the Hobnobs and ground coffee in a food processor with a good pinch of salt to the texture of breadcrumbs. With the motor still running, pour in the butter until combined. (Or put the biscuits in a freezer bag and bash to crumbs using a rolling pin. Tip into a bowl, then mix in the melted butter.)
2. Firmly press the biscuit mixture into the prepared cake tin to make a base, then chill for 30 minutes. Heat the oven to 170°C/150°C fan/gas 3½.
3. Put the dark chocolate in a heatproof bowl over a pan of barely simmering water (don’t let the water touch the bowl). Stir occasionally with a metal spoon until melted, then set aside. Put the cream cheese, sugar, 150ml soured cream, Kahlúa and coffee in a large mixing bowl and beat with an electric hand whisk until well combined and smooth. In a separate bowl beat the cornflour and eggs until smooth. Beat this mixture into the cream cheese, then stir in the melted chocolate to combine.
4. Pour the cheesecake mixture over the chilled biscuit base, then put the cake tin on a baking tray and bake for 1 hour 10 minutes until the top is firm at the edges but the centre still has a wobble. Remove from the oven (leave it on) and cool for 10 minutes.
5. Put the soured cream, caster sugar and Kahlúa in a mixing bowl and stir to combine. Pour over the cheesecake, use a spoon to smooth the top, then return to the oven and bake for 10 minutes more. Turn the oven off, open the door slightly and leave the cheesecake inside for an hour. Remove the cheesecake, cool, then chill for at least 4 hours.
6. To make the coffee syrup, bubble the coffee, Kahlúa and sugar in a pan for 6-8 minutes until syrupy. Cool.
7. Drizzle the cheesecake with the coffee syrup and scatter with chocolate coffee beans to serve.