A torch igniter includes an auxiliary fuel injector; an ignition source; and an igniter body carrying the auxiliary fuel injector and the ignition source. The igniter body includes an auxiliary combustion chamber having a side wall extending axially from a first end wall to a second end wall, the side wall defining an interior cavity between the first and second end walls. The igniter body further includes a premixing cup residing within the interior cavity including a cylindrical wall radially surrounding the auxiliary fuel injector and an auxiliary air inlet, the cylindrical wall of the premixing cup protruding axially outward relative to the first end wall of the auxiliary combustion chamber through a portion of the interior cavity to delineate a premixing zone radially inward of the cylindrical wall and a recirculation zone radially outward of the cylindrical wall.