There is growing interest in the adoption of open educational resources (OER) and open educational practices (OEP) in a variety of contexts. Continuing professional development (CPD) among practitioners in the effective adoption of OER and OEP is critical in this scenario. Massive open online courses (MOOCs), which also grew as part of the open education movement, provide a feasible means for this purpose. MOOCs are considered a 'disruptive innovation' in making free and open learning opportunities accessible to large numbers. Yet, the design of an effective massive online course that is as robust as a great online course with smaller student numbers where good principles of teaching and learning are maintained, is very challenging. Most contemporary MOOCs tend to have a content-driven focus of knowledge transmission, deviating from its original focus of knowledge generation. With the intention of providing learning experiences to promote learner engagement with OER, rather than presenting content about OER, we designed four CPD MOOCs to support the integration of OER and adoption OEP by practitioners based on a scenario-based learning (SBL) approach. This paper presents the analysis and design phases of this process, discussing the challenges faced and innovative strategies adopted in our pursuit to answer the question, "How best to design effective MOOCs on OER and OEP for continuing professional development of practitioners?" [This paper was presented at the 2018 Open Education Consortium Global Conference, held in Delft (The Netherlands) April 24th-26th, 2018.]