Preheat oven to 160°C bake. Grease a 19-21cm springform tin and line the base with baking paper.

Base
Using a food processor or rolling pin, crush the biscuits into fine crumbs. Mix in the butter and chocolate. Press firmly into the base of the prepared tin. Refrigerate while you make the filling.

Filling
In a food processor or large bowl beat together the melted chocolate, cream cheese and caster sugar. Beat in the eggs. Add the cocoa, vanilla and sour cream and mix well. Spoon the mixture evenly onto the biscuit base.

Bake for 1 hour, until puffed and just set in the centre. Leave in the oven with the door ajar and the heat turned off for 1 hour. Place in the fridge to chill until ready to serve (at least 3 hours). Decorate with pomegranate arils and serve with raspberry sauce and whipped cream.

Raspberry Sauce
Combine the raspberries and caster sugar in a small saucepan and bring to the boil. Simmer, stirring occasionally, for 6-8 minutes or until the mixture thickens slightly. Stir in the lemon juice. Refrigerate sauce for up to one week.