Scratch Encore is a collaboration between the University of Chicago, University of Maryland, and the Chicago Public Schools (CPS). It is providing an actionable and empirically-grounded answer to the question: Can we create advanced 4th-6th grade Computer Science (CS) instructional materials that give equal value to improving equity and student learning outcomes? While there are solid introductory CS curricula for 4th-6th grades, more advanced materials are either commercial offerings that are expensive, or free, ad-hoc activities that require experienced teachers. This disproportionately hurts learners in under-resourced schools that often serve underrepresented minority students. Instructional materials that advance equity cannot be designed for content and engagement alone, but instead must be vehicles through which solutions to practical barriers to equity can be mitigated. This research practitioner partnership is designing, developing, and evaluating advanced Scratch-based CS instructional materials for upper elementary students through a process that attends to practical barriers to equity.