Break the chocolate into a bowl and add the butter and syrup.Place the bowl over a pan of barely simmering water and gently melt the contents.Halve the cherries and break the bisciuts into small pieces. If you would prefer a smoother fridgecake, break the biscuits into even smaller peices.Using oven gloves, remove the chocolate from the heatand allow the bowl to cool slightly. Stir in the remaining ingredients until coated.Use cling film to cover the bottom and sides of a loaf tin. Spoon the mixture into the loaf tin and press it down with the back of a spoon.Loosely cover with more cling film and chill for 2 hours to set. Carefully turn the tin upside down on a chopping board. Remove the tin and unwrap the cling film. Leave the fridgecake to softwn for a few minutes and enjoy.