Place your packet of Oreo in the bowl of a food processor. Add the melted butter and whizz to fine crumbs. Pour the contents into a small lasagna dish, press down with the back of a spoon, then pop in the freezer for 30 minutes.
Whip your cream to soft peaks with a hand blender. Set aside. In a large mixing bowl, blend your cream cheese with your sugar. Fold through your whipped cream. Place a third of this mixture into a separate bowl. To this third, add the cocoa powder and chocolate syrup and mix to combine. To the remaining two thirds of mixture, add the peppermint extract and a few drops of green food colouring. Fold through.
Bring out your set biscuit base. Go in with your green mix. Spoon evenly over the base. Freeze for 10 minutes to firm up. Bring out, spoon over the chocolate mix and smooth out. Sprinkle over your chocolate chips.
Refrigerate for a few hours to set (or overnight if you wish). Divide into 14 pieces and serve!