Grease a 20 cm spring form cake tin and line the base and sides with baking paper.
Crush OREO cookies in a food processer to a fine crumb.
Add butter and process to combine. Press into the prepared cake tin and chill for 30 minutes.
Melt CADBURY Baking Milk Chocolate Melts in a microwave safe bowl in the microwave on high, in 30 second bursts, stirring between each burst, until smooth. Set aside to cool.
For the chocolate cheesecake filling, in a small bowl, dissolve gelatine in boiling water.
Place PHILADELPHIA cream cheese and caster sugar into the bowl of an electric mixer fitted with a balloon whisk and whip until smooth. Whip in gelatine mix, melted chocolate and cream.
Repeat steps 5 & 6 using the ingredients required for the Hazelnut cheesecake filling.
Spoon the fillings, in an alternating pattern over the set biscuit base and use a skewer to make a swirl pattern.
Refrigerate for 4 hours until firm, or preferably overnight.
Roughly chop the CADBURY DAIRY MILK Hazelnut milk chocolate block and decorate the top, then serve.