Cost-effective and responsible use of cloud computing resources (CCR) is on the business agenda of companies of all sizes. Despite this strategic goal, a typical data center produces an estimated 30% overcapacity annually. This overcapacity has severe economic and environmental consequences. Our work addresses this overcapacity by proposing a multi-sided platform for CCR trading. We initiate our research by conducting a literature review to explore the existing body of knowledge which indicates a lack of recent and evaluated platform design knowledge for CCR trading. We address this research gap by deriving and evaluating design requirements and design principles. We instantiate and evaluate the design knowledge in a respective platform framework. Thus, we contribute to research and practice by deriving and evaluating design knowledge and proposing an evaluated platform framework.