It is still debated whether Kennedy said “I am a Jelly Doughnut” to a Berlin audience in the 60s. The term ‘Berliner’ is sort of a dual meaning word with some claiming that the ein in the famous sentence implies the Jelly Doughnut version, while others say that while dropping ein is more common, it’s not improper to be there when coupled with saying you’re of Berlin. I’ve seen different people absolutely insisting in either direction. I don’t speak German, and I’m pretty sure that regardless the audience knew what he meant. But whichever side you take, it’s a very famous one.