Using a food processor, blitz all of the Oreos to a fine crumb, and mix in the melted unsalted butter.
Press this into the sides and base of a 23cm pie/flan tin. It might be easier to use your hands and fingers for this! (Make sure that the side parts are thick enough to hold once removed.) Refrigerate for now.
Filling
Spread the cookies and cream spread onto the biscuit base.
In a heatproof pan, add the double cream and heat until just boiling.
In a separate bowl, add your chocolate (chopped up) and butter, and pour on the hot cream. Whisk together until smooth!
If the chocolate mixture is still slightly not melted, heat for 10 second bursts in the microwave until combined well.
Pour the chocolate mixture onto the spread and refrigerate for an hour.
Decoration
Once the tart has set for about an hour and the ganache is still slightly soft, press in the decoration oreos. Leave to set for another 2 hours. Enjoy!
Notes
Recipe updated March 2022
Original recipe - the same base, filling - 250g milk chocolate, 250g dark chocolate, 450ml double cream, 75g icing sugar, 4-5 oreos.
Method - Melt the two chocolates and add the cream and icing sugar and whip them together. Fold through chopped Oreos and spread on the base.