There is a growing need for teacher preparation courses that support teacher candidates (TCs) in meeting requirements to obtain a supplemental teaching credential. In particular, given the demands for secondary mathematics teachers, developing effective cross-disciplinary coursework within preparation programs is timely and important work. Our study examines the development and evolution of TCs' experiences in a mathematics teaching methods course designed for TCs seeking a supplemental credential. We describe the design principles and practices used to create, and modify, a course to meet (a) state licensure requirements, (b) the goals of the teacher education program, and (c) the individual needs of the TCs. Using survey and interview data, we report on TCs' experiences with the course and their future plans for obtaining a supplemental teaching credential in mathematics. Our study contributes to discussions on teacher preparation for interdisciplinary teaching, licensure requirements, conceptual and practical tools for teaching, and effective course design.