The Building Equitable Learning Environments (BELE) network is a diverse collaborative of organizations working together to advance equity in education. The BELE Network research and learning team, and are responsible for documenting the network learnings, which are grounded in seven "Essential Actions" and reflected in shared annual aims. This brief shares learnings from BELE district partnerships around the fifth Essential Action: invest in staff. To support this Essential Action, Collaborative for Academic, Social, and Emotional Learning (CASEL) developed the Transformative (tSEL) Adult Learning Series, a set of six interactive workshops that build an opportunity for adults themselves to deepen their self-awareness and discover how they can curate equitable learning environments for young people by leveraging the five focal constructs (identity, agency, belonging, collaborative problem-solving, and curiosity). Through this series, education leaders are making investments for in-service professional learning that supports educator well-being and promotes equitable learning environments for adults and young people. Investing in staff actualizes the value of continuous improvement, which fosters a culture of expansion, growth, and development among educators.