Bath olivers are a very plain but luxurious cracker for cheese. They are quite thick and round and, as I say, perferctly plain. Chocolate Olivers are crackers wearing a very thick coat of dark chocolate...They were an essential in gift hampers for the upper middle classes for YEARS. They are an austere luxury, because they are not over sweet or fancy- very British! They come in tins, always, never boxes or packets. I remember as a little girl, when I was brought to London to see the Nutcracker or Peter Pan in the run up to Christmas, we would shop for a few staples, which would include a tin or two of Chocolate Olivers. Then, all of a sudden, a few years ago they STOPPED! It was a tragedy seen as proof by my mother's generation of the certain war against the upper middle classes! We heard in the retail press two years ago they were on the way back, but had not seen them until Ishbel, and Waitrose, made my Christmas.
Edited to add: they must not be a shop's own brand, even if dear Ishbel tried to get Fortnums own it has to be Huntley and Palmer. For those that do not know, Fortnum and Masons is a beautiful luxury food hall in London, much nicer but a little smaller then the more internationally recognised Harrods Food Halls. Fortnums also does lovely teas, and its again, a childhood memory, of beinng taken there on shopping days when we had flown to London and being aloud to choose a cake from the cake stand brought to the table.