The University of Tennessee has a Master of Mathematics (M.M.) program for secondary educators interested in college-level teaching. The program includes a capstone course on topics related to college-level teaching and can be thought of as a kind of professional development which allows secondary educators to explore options for their careers. This paper outlines the design, structure, and implementation of the course, including that it incorporated findings from an active research project. We describe details of class design, activities, our reflections, and how the course can serve as a way for teaching ideas to flourish between high school and college educators. © 2024 Taylor & Francis Group, LLC.