Rock cake

A rock cake, also called a rock bun, is a small, hard fruit cake with a rough surface resembling a rock.

Rock cakes originated in Great Britain, where they are a traditional teatime treat, but are now popular in many parts of the world. They were promoted by the Ministry of Food during the Second World War since they require fewer eggs and less sugar than ordinary cakes, an important savings in a time of strict rationing. Traditional recipes bulked them with oatmeal, which was more readily available than white flour.