Evidence about how to translate and mobilise research evidence for use in schools remains quite limited. The present study sought to address this gap by leveraging an opportunity to examine such processes. In February 2021, Edutopia (a large US-based, practice-focused educational intermediary organisation) hosted a large virtual event, with 6526 participants, to communicate/highlight just-released findings from four large-scale, funded causal studies into the efficacy of project-based learning and to encourage educators to adopt this practice. Examining this event, this primarily qualitative study addressed one main research question: How were research evidence and other forms of evidence used to justify and motivate the adoption of project-based learning in schools? This study also drew upon secondary data to examine certain self-reported impacts. This study applied a two-layered analytic frame to broadly examine the "selling" and "gelling" of educational research evidence and other forms of evidence, and to uncover if/how five main factors of innovation adoption were addressed. Findings provided detail and analysis along each of these dimensions and, further, revealed certain apparent tensions associated with making the case for project-based learning--for example, some instances of possible research 'over-selling', and a focus on answering certain questions that could not be addressed solely via research evidence, necessitating a reliance on other evidence sources. Survey/summary results suggested participants were strongly convinced of this innovation's positive impacts and were eager to discuss it further with colleagues, though given data limitations we were unable to discern the extent/ways participants' subsequent practices subsequently shifted.