Line a 20x20cm baking tray with some greaseproof paper and set aside.
Crush the digestive biscuits, either by pulsing in a blender or placing them in a freezer bag and hitting with a rolling pin. You want to leave some reasonable sized bits of biscuit to add some texture and crunch to your Rocky Road.
Place into a large bowl. Add about 3/4 of the marshmallows and all of the cherries & nuts. Set aside.
Melt the dark chocolate, butter/margarine, golden syrup, sugar and cocoa powder over a bain-marie or in short bursts in the microwave.
Once completely melted, add to the bowl of digestives, marshmallows (ect...) and mix well, ensuring everything is coated in the chocolate mixture.
Spoon the mixture into your pre-lined tray, pressing it down and paying special addition to the corners. Scatter the remaining marshmallows on top, pressing them into place.
Melt the white chocolate over a bain-marie or in short bursts in the microwave, before drizzling over the top of your Rocky Road to finish.
Leave to set in the fridge for at least 4 hours or ideally overnight, before cutting into individual portions.