Melt syrup, butter, cocoa powder, sugar and dried cranberries in a pan over a medium heat until the butter has melted and the sugar has dissolved.

Add the crushed biscuit and mix well. Pour into a greased square baking tray and put in the fridge to set.

Once set, melt the chocolate in a Pyrex dish over a pan of boiling water. Evenly spread the chocolate over the whole of the cake and leave to set.

Cut into pieces and serve with coffee.