Position the rack in the centre of the oven and preheat to 190°C (375°F) Gas mark 5.
Line a 10-inch-diameter springform tin with parchment paper.
Put the biscuits in a food processor and blitz to a fine crumb.
Add the butter and blitz again to combine.
Add the crumbs to the tin and press firmly.
Using an electric whisk, beat cream cheese and sugar in a large bowl until well blended.
Beat in the flour. Add the eggs 1 at a time, beating just until combined. Beat in the sour cream, milk, and vanilla.
Then pour the filling onto the crust.
Stir the blueberry jam in a large pan over low heat until melted. Remove from heat. Add the blueberries; toss to coat.
Spoon the blueberry mixture over top of the cake, spreading evenly.
Bake cheesecake for 10 minutes and then reduce heat to 140°C (275°F) Gas mark 1 for 30 minutes.
Turn off the oven; keep the door closed and let the cheesecake stand in the oven for 1 hour.
Refrigerate until cold, at least 4 hours, or overnight.
Run a small sharp knife around the sides of the cake to loosen it. Release pan sides.
Transfer the cake to a platter and it is ready to serve.