Reflection is widely recognized as a pathway to deeper learning in higher education, yet many students struggle to engage in reflective tasks meaningfully. This study examined how student engagement and reflective performance developed across a seven-session structured reflective learning sequence in an undergraduate course. A longitudinal quantitative design was employed, including 59 students for participation data and 38 students for performance analysis. The instructional design incorporated teacher-led scaffolding, including exemplars, feedback, and structured prompts, with optional AI-supported assistance in later sessions. Results showed that engagement patterns were non-linear. Submission rates increased following the introduction of exemplars and feedback, declined when higher-order reflection was first introduced, and stabilized in later sessions, with the lowest participation observed in the final integrative task. Reflective performance also differed across stages. Step 1 (descriptive reflection) scores improved progressively, whereas Step 2 (analytical reflection) scores remained consistently high among students who completed substantive responses. The gap between attempted and completed Step 2 responses decreased over time. These findings suggest that reflective learning develops gradually and is sensitive to instructional conditions. The study highlights reflection as a staged developmental process and underscores the role of structured support in facilitating student engagement and performance.