I adore these. “See Banbury cake” is misleading, however: the Eccles cake is far more famed (and widely available!).
They're not so small either. A good one can be more the size of a pasty than a mince pie. Of course, that's not a patch on the size of a Victoria sponge or other “real”, flour-eggs-milk-and-butter cake.
An Eccles cake is a small, round cake filled with currants and made with puff pastry, enriched with butter and topped with demerara sugar.
Eccles cakes are named after the English town of Eccles, in Salford. It is not known who invented the recipe, but James Birch is credited with being the first person to sell Eccles cakes on a commercial basis, from his shop at the corner of Vicarage Road and St Mary’s Road (now known as Church Street) in the town centre, in 1793.
Nicknames for the Eccles cake include Squashed Fly Cake and Fly Cake, owing to the appearance of the currants that it contains. _Wikipedia