This document presents a framework for CrAFt Cities process learning using Mutual Learning Exercises, based on the City as a Commons approach and principles of the New European Bauhaus. It is co-designed by CrAFt partners and inspired by previous experiences from the H2020-funded Smart Cities and Communities Lighthouse projects. CrAFt defines process learning as a combination of social and organisational learning that leads to empowerment of local stakeholders, coordinated systematic changes and broader transformation or urban governance. Process learning is generated by the interaction of local actors with innovative solutions through which they learn how to mainstream innovative and sustainable practices. This results in an increased capacity of individuals, organisations and complex stakeholder ecosystems to transform and utilise innovative approaches. The CrAFt Cities consist of 3 Sandbox Cities (Amsterdam, Bologna and Prague) and 60 Reference Cities or clusters of cities. All CrAFt Cities will be invited to participate in mutual learning and to share and implement approaches supporting learning on a local level. CrAFt Cities will also mutually learn how to enhance process learning on local level in order to create transformative experiences for local stakeholders which result in wider organisational transformations and the development of new relationships, competences, and roles within the local ecosystem. The key tool for supporting learning between cities are Mutual Learning Exercises (MLEs) - physical, online or hybrid meetings with CrAFt Cities, consortium partners and invited guests enabling cities to share lessons and implement solutions provided in CrAFt. The framework presents goals and principles for MLEs in CrAFt, as well as mechanisms of capturing and implementing key lessons. Furthermore, the document presents how learning and feedback gathered through MLEs will be shared within CrAFt with all partners in order to inform their work.