To make the cheesecake base, melt the butter in the microwave on short bursts on in a small pan over a medium heat.
Blitz the biscuits in a food processor to a small crumb, add the melted butter, and pulse a few times until it is combined well.
Dip into a 8″/20cm deep tin and press down firmly. Chill in the refrigerator whilst you do the rest.
To make the Cheesecake Filling - melt the chocolate in a bowl over a pan of gently simmering water, stirring gently or microwave in short bursts until fully melted. Leave to cool slightly whilst doing the rest.
With an electric mixer, whisk the Cream Cheese, vanilla and icing sugar until combined. Pour in the liquid double cream and continue to whip the cream cheese/cream mixture until it is starting to thicken a lot like a mousse does.
Whilst mixing, pour in the melted chocolate and Whip again until thick – It will hold it self completely when finished whipping – It won’t take too long as the chocolate will harden quickly and cause it to thicken.
Chop up the crunchies and fold through the mixture. Pour the mix on to the biscuit base, smooth over, cover, and chill in the fridge for at least 5-6 hours hours or preferably overnight.