I was curious about French Toast the other day. Turns out it was invented by someone with the last name French and the intention was to call it French's Toast. But when he printed the name, he forgot the apostrophe and 'S'!
Similar story with German chocolate cake. It was German's chocolate cake. A guy named German.
That's a legend; the name was used in England before the mythical Mr. French existed in the US!
(also French Toast was invented at least before the 6th Century)