Melt golden syrup, chocolate and coconut oil in a bowl over boiling water. Pour about ⅓ of this mixture into a small bowl and set aside.

Crush biscuits in a freezer bag with a rolling pin. Continue until you have a mixture of big and small pieces of biscuit.

Pour biscuits, mini marshmallows and coconut into the larger amount of chocolate mixture. Stir well.

Fold out onto a tray lined with baking paper and smooth out. Cover over with the chocolate mixture you set aside earlier.

Allow to set in the fridge for at least an hour. Cut into squares and sprinkle dessicated coconut over the top.