Coffee cake conundrum

Question: if you ordered a piece of lemon cake in a coffee shop and the cake was vanilla, would you feel you had been shortchanged and consider suing for false advertising?
I was at a meeting today where we (amongst other things) collected toys to be given to a charity (Kinderschutzambulanz, a counselling centre for mentally, physically, sexually & emotionally abused children.). To get all the toys into my friend's car we had to take the roof down...
Anyway, back to the cake. There was coffee cake on offer at the meeting, which turned out to be normal cake, not coffee flavoured in he slightest, which was a huge shock to the three Brits there. Coffee cake to Americans, is just cake that is served with coffee, apparently...which makes me wonder about passionfruit cake