Preheat the oven to 160oC/Gas Mark 4.
Put the oreo cookies in a plastic bag and crush into crumbs with a rolling pin or blitz in a mini chopper.
Melt the butter, combine with the cookie crumbs, and mix well.
Press the cookie mix into the base of the 23cm spring form cake tin and compact well together with the back of a spoon.
Bake in the oven for 10 minutes, take out and leave to cool. Switch off the oven.
Put the jelly in a microwave proof jug with 100ml cold water and microwave for 1 minute. Mix well until fully dissolved.
Bring the level of the jelly up to 400ml in the jug by adding in either the juice of the lemon and cold water or the strawberry syrup from the can of strawberries (depending on which version you are making.)
Place the jelly in the fridge to set for 1 hour.
Lightly whip 150ml of cream until just beginning to form peaks and set aside.
Use an electric mixer to cream the Philadelphia cheese and semi-set jelly together with 50g icing sugar until smooth.
Fold the cream and strained canned strawberries or a handful of fresh raspberries into the cheesecake mix and pour over the Oreo cookie base.
Leave to set for a few hours or ideally overnight.
Serve decorated with fresh strawberries and grated chocolate or fresh raspberries and lemon zest.