Combine oreo cookies crumbs with melted butter in a bowl and press into base of round 6 inch cake tin. Chill in fridge whilst preparing filling
Place chopped chocolate in a microwavable bowl and microwave at 30 second bursts stirring in between until chocolate has melted
Whilst chocolate mixture cools, whisk together gelatine and water in a small bowl and allow gelatin to bloom. When the chocolate is at room temperature microwave bowl of gelatin for 15 seconds until melted. Whisk gelatin into chocolate mixture and set aside.
Beat together mascarpone cheese, cream cheese and sugar in a bowl until smooth. Stir in melted chocolate mixture until smooth
Whip cream in bowl of stand mixer until stiff peaks form and then gently fold in cheese mixture, followed by raspberry puree. Mix in whole raspberries.
Pour filling onto oreo cookie base and smooth over top with spatula. Cover and put in fridge to chill for 4 hours or overnight.