Crack the chocolate into pieces and stick in a heat-proof bowl with the butter and syrup.
Melt this over a pan of simmering water until smooth and glossy.
Crumble the biscuits into small pieces and stir into the dried fruit, coconut and marshmallows.
Pour all of these into the melted chocolate mixture and stir to combine and coat.
Line a rectangular cake tin with cling film.
Transfer the rocky road to the lined tin and leave to set up in the fridge for a couple of hours.
Tip out onto a board and cut into chunky squares.
Feel free to add a handful of whatever you like into this instead of the coconut, sultanas and marshmallows. It's all about making it personal. Just make sure there's a mixture of textures. Nuts, honeycomb or fudge pieces are also great.