Place broken chocolate in a microwave safe bowl and heat in 30 second increments until melted and smooth.
Place biscuits in a large zip lock bag and bash with a rolling pin until roughly crushed (with large pieces remaining).
Stir two-thirds of the broken biscuits and the coconut into the melted chocolate.
Tip mixture out onto a tray lined with baking paper and spread out with a spatula. Sprinkle with remaining broken biscuits.
Refrigerate for 1 hour or until set. Cut into jagged pieces and serve,