It's pronounced "shoor-feen-ah." It was Italian.
Say what you will about the old days of advertising: they shur could come up with snappy, unique campaigns. I mean, for goodness sake, "For 'GOODness' sake' - such a line never occured to anyone before? Oh but we'll put goodness in quotes and put GOOD in caps to emphasize that it's tasty as well as wholesome. You see?
Of course I see; do you think I'm stupid? It's the most obvious thing in the world.