Place the premade crust, still in its foil dish, on a flat baking sheet. Peel back the edges of the foil so that you uncover the rim of the graham cracker case.
Preheat the oven to 180C (160C fan, 355F).
Put the cream cheese, double cream, vanilla, eggs, plain flour, and caster sugar in a bowl. Whisk together until just combined - don't continue to whisk as this will introduce air bubbles.
Pour the filling into the prepared case.
Bake for 45 mins until firm. When shaken, it should wobbly but not ripple.
Stand the baking sheet on a wire rack to allow your cheesecake to cool in the tin.
Once cooled, cover and chill overnight.
After chilling, your cheesecake should be firm and ready to serve however you like.
Top with fresh berries and slice with a sharp knife to serve.