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 150C. 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.