A capsule for a heat-not-burn (HNB) aerosol-generating device may include a first heater, a second heater, and a frame sandwiched between the first heater and the second heater, and a cannabinoid-containing material. The frame may define open spaces therein and have a rigidity that is adequate to support the first heater and the second heater. The open spaces within the frame may be interconnected and sized for aerosol-permeability and capillary action.