To make the poached cherries, combine the cherries, sugar, cinnamon, star anise and water in a saucepan. Place over low heat. Cook, stirring occasionally, for 5 mins or until cherries are heated through and start to release their juices. Drain into a large bowl. Return the syrup to the saucepan. Combine the cornflour with extra water in a bowl. Add to the cherry liquid and place over high heat. Cook, stirring, for 2-3 mins or until sauce boils and thickens. Pour hot syrup over the cherries. Place in the fridge to chill.
To make the crust, place the biscuits in a food processor and process until finely crushed. Add the butter and process until well combined. Spoon into a 10cm x 34cm rectangular tart tin with removable base. Press over the base and sides of the pan. Place in the fridge for 30 mins to set.
Preheat oven to 150°C. To make the filling, place cream cheese, sugar, eggs and sour cream in a food processor and process until smooth. With the motor running, add the chocolate and process until combined and mixture is smooth. Pour into the pastry case. Place on a baking tray. Bake for 30-35 mins or until cheesecake is just set. Leave the cheesecake in the oven, with the door ajar, to cool to room temperature. Place in the fridge for 2-3 hours to chill.
Use an electric mixer to whisk the cream, icing sugar and vanilla bean paste in a bowl until soft peaks form.
Transfer the cheesecake to a serving plate. Top with cream mixture. Spoon over the poached cherries with a little of the sauce. Cut into slices to serve.