Step 1

Lightly oil the base of a 23cm spring-form tin. Melt the butter in a pan, stir in the crushed biscuits and press on to the base of the tin with the back of a spoon. Chill while you make the filling.

Step 2

Melt the chocolate in a bowl over a pan of gently simmering water, stirring halfway through. Remove the bowl from the pan. Preheat the oven to 160C/gas 3/fan 140C.

Step 3

Beat the cheese and sugar together with an electric hand mixer until fluffy. Add the eggs, one at a time, but don’t over-beat. With the beater on low speed, blend in the melted chocolate, the cream and the Kahlúa. Pour on to the biscuit base and bake on a baking sheet for 55 minutes-1 hour or until set. Test by touching the surface, which should be shiny, and a bit wobbly and darker in the centre. Loosen the cheesecake from the tin with a round-bladed knife and leave to cool. Chill for 3 hours or overnight.

Step 4

Take the cheesecake from the tin. For the topping, combine the crème fraîche with the Kahlúa and spread over the top. Dust lightly with cocoa powder and serve in wedges with a little Kahlúa poured over each slice.