Baked Blueberry Cheesecake

50g butter
200g ginger biscuits, crushed
few drops vanilla essence
400g mascarpone
350g cream cheese
125g caster sugar
2 tbsp cornflour
3 eggs
1 orange, zest
300g blueberries

1. Grease a deep 24cm tin
2. Melt the butter
3. Stir in the biscuits
4. Press into tin to form a base
5. Chill
6. Beat remaining ingredients
7. Fold in the blueberries
8. Bake 180, GM4 45 mins – 1 hr