A 72-year-old woman with a history of multiple solar keratoses presents with a 2 cm erythematous, scaly plaque on the forehead that has been present for 2 years. The lesion is flat with ill-defined borders and does not ulcerate. On dermoscopy, there is a homogeneous erythematous area with fine scaling. Biopsy reveals basaloid cells in the superficial dermis with a broad, pushing border. What is the most likely subtype of basal cell carcinoma?