Growing interest in CS has led to a shortage of qualified educators for K-12 level instruction. Many out-of-school-time computing programs are led by well-intentioned individuals with little formal training in education such as undergraduate students pursuing computing degrees. This results in environments that are often not conducive to learning for students coming from diverse cultural and educational backgrounds. I addressed some of these challenges by using undergraduates as coaches in K-12 outreach CS activities for underrepresented students. These coaches are given essential pedagogical training with playful material that allows them to succeed as educators.