You will need a detachable baking pan.alternatively,line a normal baking pan with cling film or foil.

Crush the oreos either in a food processor or using a rolling pin until crumbly(like breadcrumbs).Add the melted butter and mix well. Pour the mixture into the baking pan and press down until flat,even and compact.

Meanwhile,heat one cup of the unwhipped cream and add it into the chocolate to melt it. Stir until well melted. Let it come down to room temperature.

Add three cups of whipped cream and fold it in until well mixed.pour this filling into the oreo crust and even it out.