A conveyor oven having a heating chamber and an oven chamber. A conveyor is disposed in the oven chamber to convey food products between an entry port and an exit port. An air impingement assembly is disposed to provide jets of impingement air toward the food product. A fan blower, a heater and a moisture delivery device are arranged to provide heat and moisture to an airflow to the air impingement assembly so that the jets of air are heated and laden with moisture and provide as a blanket-like mixture of air and moisture at the surface of the food product.