In Britain we call them Chocolate bars as opposed to candy bars, and that 'flakey candy bar' is known as a Flake. Although you can purchase them in most shops that sell 'candy bars' they're most often seen in the top of an ice cream cone or decorating a sundae.

There was also an ad campaign, lasting decades, called the flake girls. featuring young women indulging themselves. Marketing the Flake as something of luxury.