I can't personally vouch for this recipe, as it contains dairy, and lots of it. I am on a dairy-free diet as it helps with pain management, but those who ingested the resulting cake assured me it was delicious. It uses light cream cheese and not much sugar as the birthday mum is diabetic. (Note - I do not measure things)
Take a packet granita biscuits and process to fine-ish crumbs. Melt enough butter to hold the crumbs together and not let any cheesecake mixture through and mix with the crumbs (use a microwave for this). Push biscuit base into springform tin and set in fridge for about 3 hours or more.
Process 2 packets of light philly cream cheese till very smooth. Add a couple of soup spoonfuls of light sour cream, the same amount of cream, about 2 tsp of vanilla essence (the real thing) and process till mixed. Add a little raw caster sugar (Why raw? It tastes better) Probably about 1 tbsp. Process again. Boil water, put 3-4 tsp gelatine in a jug, add enough boiling water to dissolve it. Let it cool a bit (don't put it in the fridge!) and pour into cheesecake mixture blending continuously. Keep blending for a bit. Pour cheesecake mixture into chilled base.
In a blender or bowl (to be mixed with a hand blender) put a large handful of strawberries (de-greened) and several spoonfuls of canned raspberries (without too much syrup). Blend until there are no lumps of berry to be seen. Pour berry mixture into cheesecake and create a swirly marble effect with a knife, being careful not to disturb the crust. (Note: this results in a creamy, not quite set, swirled berry layer on top of a set vanilla cheesecake layer. If you want swirliness all the way through, you could try adding the berries and cheesecake mix to a bowl, mixing ever so slightly and pouring into the base).
Set in fridge for a long time (overnight). Serve with a bit of extra whipped cream and fresh strawberries.