Place dark chocolate, butter, whiskey and condensed milk in a heated bain-marie. Allow to very gently melt.
When mixture is completely smooth, remove from heat. Allow to cook slightly.
Add white chocolate pieces, marshmallows, nuts and crushed biscuits.
Gently mix together, ensuring not to break up the white chocolate and biscuits too much. The mixture should be chunky.
Transer to a non-stick container (I like to use a springform cake tin), pressing down firmly and immediately put in the refrigerator.
When chilled completely, drizzle the melted white chocolate over the top and allow to set.
Cut into pieces and enjoy!
Submitted by: Déirdre
