A method of producing a cereal bar is provided in which the cereal comprises a cereal mixture including ready-to-eat (RTE) cereal pieces joined together with a binder, where the cereal and binder together form a cereal matrix which is heated for a time and temperature to reduce the water activity of the external portion thereof while maintaining an internal portion of the cereal matrix at a higher second water activity. The method provides cereal bars requiring less compressive force to be formed into a cohesive self-supporting structure in providing a chewy reduced-density cereal bar with improved shelf life.