Place the Oreos in a food processor and blitz until they resemble bread crumbs.
Pour the melted butter over the crumbs and pulse until mixed well.
Press the mixture into a tart pan using your fingers and the back of a measuring cup. Place in the fridge to chill.
Meanwhile, heat the cream over medium heat until bubbles start to appear around the edges but do not boil or simmer. Remove from the heat and pour over the chocolate chips.
Leave for a minute or two then start to stir until you have a smooth chocolate ganache.
Pour this over the chilled crust then place in the fridge for at least three hours or overnight.
Before serving, remove from the tart pan, shave over some white chocolate and dust with icing sugar or cover with fresh berries.