Writing is important for science, technology, engineering, and math (STEM) graduate students to achieve milestones within their programs and for their future career aspirations. However, although STEM graduate students engage in a variety of academic writing activities in their time as doctoral students, writing development has not always been a focus of STEM higher education programs. We designed and implemented a 10-week, one-credit professional development course to support the academic reading and writing practices of first-year chemistry graduate students at a large R1 institution. Students end the course having completed a short independent research proposal and having received structured feedback from the department community. The course scaffolds the students' writing, integrates collaborative activities such as peer review, and explores social connections as a salient component of not only writing practice but also the graduate school experience. We iteratively designed, implemented, and evaluated the professional development course. Here, we describe the teaching approaches and course contents used to support students' chemistry writing process. This course may guide the creation of professional development courses to support chemistry graduate students' writing development at other PhD-granting institutions, and it may be adapted to support academic writing across STEM disciplines.