Conducting K-12 outreach programs on university or college campuses focused on science, technology, engineering, and mathematics (STEM) disciplines is an essential part of the multifaceted effort for preparing future generations of engineers and scientists. However, the lack of structured frameworks to design and deliver activities and programs that maximize potential impacts poses a challenge. This case study contributes to filling this gap by presenting a six-step adaptable pedagogical framework whose intent is to provide meaningful structure for on-campus STEM outreach activities that emphasize collaborative, hands-on learning experiences for pre-college students. Successful implementation of the framework is demonstrated through the design of a civil engineering workshop on sustainable and hazard-resistant earth masonry, and its evaluation through the analysis of the feedback of 85 participants from three summer workshops for high school students between 2017 and 2019.