A pedagogical innovation was collaboratively designed, implemented and evaluated in the context of a school-university partnership. The innovation had a dual purpose: 1) to provide an opportunity for primary pre-service teachers to develop their understanding and experience of teaching "design and produce" processes (working technologically), and 2) to involve primary children in a highly engaging, meaningful learning experience with high visibility in the school's community. We decided that this could best take the form of an annual whole school "Design and Make Day" (DM Day). In this paper, we describe the context of the DM Day, spotlight three of the tasks, and share the key findings from the project evaluation.