Baked blueberry and mascarpone cheesecake

Method

1. Preheat the oven to 180°C/fan160°C/gas 4. Grease a deep, 24cm non-stick springform cake tin with butter. Mix the biscuit crumbs with the melted butter and spoon into the tin. Pat down evenly and firmly with the back of a metal spoon to form the base. Chill for 10 minutes.
2. Split the vanilla pod and scrape out the seeds with the tip of a small knife (keep the pod for making vanilla sugar). Put the seeds in a large bowl with the mascarpone, cream cheese, caster sugar, cornflour, eggs and orange zest. Using an electric whisk, beat until well blended.
3. Stir all but a handful of the blueberries into the mixture and pour it into the tin. Put the tin on a baking sheet, then scatter over the remaining blueberries, pushing them into the mixture. Bake for 45 minutes to 1 hour until golden brown and almost set – it will still be a little wobbly in the centre but will firm up as it cools. Open the oven door, but leave the cheesecake to cool inside the oven before removing it from the tin. Chill, covered, for a few hours or overnight, then serve.