Found this
Chocolate Tiffin (also known as Chocolate Concrete).
(makes one cob)
4 oz butter or margarine
1 tablespoon sugar
2 tablespoons drinking chocolate
1 tablespoon golden syrup
2 tablespoons raisins
8oz Rich Tea or plain biscuits
5oz Bournville or good quality milk chocolate
Melt the butter and sugar with the syrup in a large pan. Add the
raisins and drinking chocolate and bring to the boil. Allow to
bubble gently for two to three minutes to thicken a little. Meanwhile,
crush the biscuits with a rolling pin. Alternatively, you can grind
them in a food processor to give crumbs, depending on whether you
prefer a smooth or chunky effect. Don't leave the biscuit pieces
too large, however, or the finished slab will tend to break up when
cut. Mix the crumbs well into the melted mixture, coating thoroughly,
press into a lined 7ins by 11ins shallow Swiss roll tin and level
out, pushing down the mixture well. Melt the chocolate carefully
and spread over the top. Leave to set in a cool place then cut into
15 or 24 pieces with a sharp knife. (Other curious names for this
recipe include rocky road squares, chocolate concrete or the rather
dubious sounding cement!) -recipecottage.com
Is it also called tiffin ?