 A bacon sandwich (also known in the UK as a bacon sarnie, bacon butty/buttie, bacon bap, bacon barm, bacon batch or bacon cob and as a bacon sanger or piece 'n bacon in Scotland) is a form of sandwich made from cooked bacon between two slices of bread, usually buttered.Often some form of sauce, such as mayonnaise, tomato ketchup or brown sauce, is included.A Cheese & Bacon roll is a common snack popular in Australia which usually consists of a hamburger bun topped with cheese and bacon.