This paper showcases the development and implementation of a year-long, job-embedded professional development (PD) program designed for a small private elementary school. Utilizing an action research framework of planning, acting, observing, and reflecting, the PD aimed to enhance teachers' pedagogical content knowledge (PCK) and foster their mathematical creativity, ultimately facilitating students' creative thinking in mathematics. The findings suggest the importance of sustained, iterative support in PD to cultivate teachers' confidence and ability to implement creative pedagogies, thereby transforming mathematics education to value inquiry and creative reasoning.