Small, mature businesses often struggle with leadership development due to limited time, skills, processes, and resources. This lack of leadership is a significant factor in the failure of these businesses. While extensive research exists on leaders' skills, behaviors, competencies, experience, and attributes, a notable gap remains in the literature regarding effective leader development processes within the dynamic yet flat organizational structures of small businesses. This clinical research study addresses this gap by exploring the effectiveness of a leader-led transformative adult learning process in developing leader candidates within a small, mature business. Transformative learning, which involves critical reflection, experiential learning, and perspective transformation, was examined for its potential to cultivate influential leaders efficiently. Adopting a pragmatic research paradigm, the study employed a Leader Elevated Development Model (LEDM) grounded in transformative learning theory. This leader development program guided select candidates through transformative critical thinking skills and foundational emotional intelligence. The clinical research study adhered to the boundaries developed by Edgar Schein and employed guided and informed interventions. The effectiveness of the adult learning process was evaluated using emotional intelligence assessments at the beginning and end of an eight-week program, as well as independent observations of engagement and behaviors, participant feedback, and leadership-level self-assessments. The key findings indicate that participants improved their emotional intelligence, sustained enhanced engagement, and displayed positive behavioral changes. However, eight weeks was not enough time to transition leader candidates from a self-leadership level to a team or organizational leadership level. The leader-facilitated development program effectively fostered leaders who were more capable of ensuring long-term business success by overcoming antecedent habits of mind and enhancing critical thinking skills. It provides a model for small, mature businesses to emulate. Furthermore, the study found that as an adult learning theory, transformative learning theory is an effective tool for business education.