Lightly grease an 8 or 9 inch square pan and line with baking paper.
Put the chocolate chips, Biscoff spread, butter and golden syrup in a large bowl and microwave, in 30 second bursts and stirring in between until melted.
Add the biscuits and mini marshmallows and gently fold them into the chocolate.
Spread the mixture into the prepared tin, pressing down firmly to level.
Top with the melted Biscoff spread, spreading to cover the entire surface.
Add biscuits on top to decorate, pressing them down so that they stick. Chill for two hours or until the rocky road has set.
Cut into small squares using a large knife. Store the rocky road in the fridge for up to four days.