Baking is a food cooking method using prolonged dry heat acting by convection, rather than by thermal radiation, normally in an oven, but also in hot ashes, or on hot stones. The most common baked item is bread but many other types of foods are baked. Heat is gradually transferred "from the surface of cakes, cookies and breads to their centre. As heat travels through it transforms batters and doughs into baked goods with a firm dry crust and a softer centre". Baking can be combined with grilling to produce a hybrid barbecue variant, by using both methods simultaneously or one before the other, cooking twice. Baking is related to barbecuing because the concept of the masonry oven is similar to that of a smoke pit.