Extended Reality (XR) technologies are increasingly used in education and workforce training; however, their implementation often lacks alignment with instructional design principles and learning theory. This gap limits the effectiveness, scalability, and transferability of XR-based learning experiences. This paper presents the KonnectXR (KXR) Instructional Design Framework, a structured, theory-informed approach for designing XR learning environments that align pedagogy, technology, and accessibility. Unlike approaches that emphasize technology selection or isolated pedagogical strategies, the KXR framework provides an integrated model that connects XR affordances with instructional design processes and adult learning theory. The framework integrates Backward Design and the ADDIE model into a unified XR-specific process that aligns learning objectives, instructional activities, and assessment strategies. It is refined through iterative application in higher education and workforce training contexts, with representative cases illustrating how XR modalities (e.g., 360°, AR, MR, VR) are selected and implemented based on instructional goals and contextual constraints. The KXR framework offers a practical, theoretically grounded approach to developing immersive, outcome-oriented learning experiences and provides a foundation for future empirical research.