Jaffa Cakes are cakes, as the name suggests and contrary to the claims of HM Customs and Excise, who argued that they were biscuits. This was not an exercise in pedantry but an attempt to levy VAT on them: cakes are `food' and zero rated, while biscuits are `luxury items', and attract 17.5% tax. (Note that the McVities Jaffa Cake web site calls them `biscuits' anyway....)
The matter was settled with this test: a cake starts off soft and goes hard when it is stale, but a biscuit starts off hard and goes soft when stale. Jaffa Cakes harden when stale.
