A new cultivar of Stachys plant, ‘Pink Cotton Candy’, characterized by its flowers that are bright pink and two-toned in color with the upper lip of the petals lighter pink in color than the lower lip of the petals, its combination of newly opened flowers and fading flowers that impart an addition two-tone effect to the inflorescences, its free-flowering habit with an abundance of blooms produces for at least 8 weeks during the summer months, its robust and dense mound of deep green foliage with upright flowering stems arising above the foliage, and its hardiness in U.S.D.A Zones 4 to 8.