Grease a 15 x 15 cm (6 x 6 inch) baking tin. Gently heat the butter, 150 g (5 oz) of the chocolate and the golden syrup in a saucepan until melted and smooth. Stir in the crushed biscuits, apricots, cherries and coconut until evenly coated in the chocolate. Tip the mixture into the prepared tin and roughly spread level.
Melt the remaining chocolate in a microwaveable bowl in a microwave on Medium, checking every 30 seconds until melted and smooth. Drizzle over the biscuit mixture. Cover and chill in the freezer for 15 minutes until firm.