One type of heating assembly that has been proposed for heated smoking devices operates by inserting a heater into a solid aerosol-forming substrate, such as a plug of tobacco. This arrangement allows the substrate to be heated directly and efficiently. But there are number of technical challenges with this type of heating assembly, including meeting requirements for small size, robustness, low manufacturing cost, sufficient operating temperatures and effective localisation of generated heat. A heating assembly for heating an aerosol-forming substrate is disclosed, the heating assembly comprising: a heater comprising an electrically resistive heating element and a heater substrate； and a heater mount coupled to the heater； wherein the heating element comprises a first portion and a second portion configured such that, when an electrical current is passed through the heating element the first portion is heated to a higher temperature than the second portion as a result of the electrical current； and wherein the heater mount surrounds the second portion of the heating element.
