The Cro-Nut - from Paris Baguette, March 13, 2014
wikipedia, has it that it was invented by chef Dominique Ansel in New York City. The croissant part comes from the fact that it's a laminated dough (butter folded into sheets of dough and folded over and over again) and the doughnut contributes not only the round shape but the sugar coating, the filling and the glaze on top. It's actually pretty genius when you think about it; this is the kind of food modification I can deal with.
Paris Baguette last week. I was actually at a food court next door getting takeout for my dinner and stopped off at Paris Baguette to see if there was anything I wanted for dessert. Lo and behold, there sat a tray of cronuts. So I bought one for $3.75. Not exactly cheap if you think of it as a doughnut (Stan's Donuts are 85 cents each) but in line with croissant prices.