Crush biscuits in a blender then add 250g of melted butter and mix. Line a tray with parchment paper. Spread your mixture onto the bottom of your tray and flatten with the back on a wooden spoon. Chill for 20 minutes.

Melt 150g of remaining butter in a pan over medium heat. Add sugar and mix. When it dissolves add the condensed mix can and mix. Bring to a boil while continuously stirring. Then lower down to a simmer and keep stirring for 2 minutes till the mixture thickens. Pour onto your biscuit base. Chill for 30 minutes.

Break up the chocolate and either melt in microwave at 30 second intervals while stirring in between each time. Or melt over hot water bath. Pour onto your prepared tray and chill for 2 hours.