The Kaiser Roll, also called Vienna roll, is a kind of bread roll, popular in the United States and Canada. It is typically a crusty round roll, often sprinkled on top with poppy or sesame seeds, made by folding corners of a square inward so that their points meet. It is often used as a bun for sandwiches, including hamburgers. It was supposedly invented in Vienna, and is thought to have been named to honor Emperor Franz Josef. A kaiser roll and a hard roll are two completely different types of rolls.
