Abstract: A reusable mold and method for applying stucco to intersecting planar surfaces to create a quoin is disclosed. The mold is a generally rectangular framework of non-adhering surfaces. Preferably, each mold has two longitudinal members and at least two non-continuous mated cross members which are hingedly joined so that the mold can bend at its transverse midpoint to rest flat against two adjacent planar surfaces. In use, a cement base coat is placed on the surfaces. The mold is tacked in place and the open areas of the mold are filled with cement to form quoins. After the quoins harden, the mold is removed and the entire surface, including molded quoin, is finished with stucco.