With about ten seats or less, Le nanan (르낫농) is a really tiny cafe just beside one of the popular restaurants in Yeonnamdong (which I found overrated). A friend who knows a thing or two about pastry recommended this cafe, which I probably would not have thought of entering otherwise because of its modest exterior.
Perhaps the good thing about writing about a place after some time has passed is this: If you don’t remember if something was good (or bad), it probably didn’t make a deep enough impression.
My friend likes this cafe, but it has since closed down. It should be moving to a new place soon, however.