Croissants were made to be dunked into coffee, right? Doesn’t the very shape lends itself to dunking?
One of the first things I fell in love with in France was the general acceptance, albeit a bit common, of dunking my morning baguette-and-butter tartine or croissant in my café au lait. Dunking was forbidden in my mother’s house. She said it was common and thought Dunkin’ Donuts a travesty, so the French acceptance, though not formal, made me feel the reins of my upbringing had been loosened, if not removed.
Some French people, like Mme Verdurin in Proust’s Le Temps Retrouvé / Time Regained, actually suffer when they’re not allowed to dunk:
Mrs. Verdurin, suffering with migraines from no longer having a croissant to dunk in her café au lait, had gotten a prescription from Dr. Cottard allowing her to do it in certain restaurants, which we talked about. This was almost as difficult as getting the government to nominate a general. She ate her first croissant on the morning the newspapers reported the sinking of the Lusitania.