The British chocolate-covered biscuit whose legal classification was tested in court in 1991 is the Jaffa Cake.
Jaffa Cakes are small, round cakes made with a sponge base, an orange-flavoured jelly layer, and a coating of chocolate. McVitie’s introduced them in the United Kingdom in 1927, and the product was named after Jaffa oranges or the associated orange flavour.
In 1991, a tax dispute in the United Kingdom examined whether Jaffa Cakes should be treated as biscuits or cakes. The distinction mattered because value-added tax rules treated biscuits differently from cakes. McVitie’s successfully argued that the product was a cake, citing features including its texture and the way it becomes hard rather than soft when stale.
The case made Jaffa Cakes a famous example of food classification in British law. Their name is a brand name, so other manufacturers may sell similar orange-and-chocolate products under different names.