Jaffa Cakes

Jaffa Cakes are a small kind of sweet snack that are named after the Jaffa orange. They are made with orange-flavored jam, and chocolate. McVitie and Price introduced them in the United Kingdom in 1927. Even though they look like biscuits, a court ruled that they are actually cakes. The court case was because biscuits are taxed differently than cakes. 
McVitie's did not register the name "Jaffa Cakes" as a trademark. For this reason, other biscuit manufacturers and supermarkets have made similar products under the same name. The product's classification as a cake or biscuit was part of a VAT tribunal in 1991, with the court finding in McVitie's favour that the Jaffa cake should be considered a cake for tax purposes. In 2012 they were ranked the best selling cake or biscuit in the United Kingdom.