An energy saving insulated roofing shingle and related method of manufacturing. One embodiment of the shingle has an insulator attached to, or formed as part of, the interior surface of an outer layer across a portion of the headlap area about equal to the designed exposure surface area of the installed shingle. The insulation reduces the heat absorbed by the shingle and transmitted into the deck that in turn heats the attic space. The disclosed principles reduce the heat load directed into a building from the sun. In addition, the thickness of the insulation under the shingle nailing area may be minimized, thereby allowing for the normal asphalt shingle surfaces to lay against each other. Moreover, to reduce the overall shingle thickness, the insulation could replace all or part of the backsurfacing materials applied to the back of shingles in the location where the insulation is added. Additionally, asphalt applied to the back of the shingle could be reduced to accommodate insulation thickness.