This study employed an embedded mixed-methods quasi-experimental design at Hidassie Secondary School in the Kambata Zone of Central Ethiopia to examine the effects of explicit and implicit written corrective feedback (WCF) on the writing quality of Grade 11 EFL students, categorized into explicit (n=31), implicit (n=30, and comparison (n=27) groups. Quantitative data were collected through tests and analyzed using descriptive statistics, t-tests, ANOVA and MANOVA, while think-aloud protocols (TAP) and semi-structured interviews explored students’ cognitive, affective, and behavioral engagement and perceptions. The research demonstrated that while both feedback types enhanced improvement in writing quality, explicit feedback produced statistically significant advantage (p < .001) over implicit and control groups, whereas the variation between implicit and control conditions remained statistically non-significant (p > .05) over time. While all writing components exhibited improvements and large effect sizes, ranging from the threshold .14 to .325, lexical resources showed the largest effect size at η² = .325. Crucially, the qualitative findings revealed a paradox between performance and cognitive engagement. Explicit feedback facilitated higher revision success through direct, often surface- level noticing, but implicit feedback fostered deeper cognitive processing and linguistic synthesis despite resulting in lower immediate test scores. Furthermore, students across all groups exhibited a similar affective reaction, transitioning from initial confusion to eventual appreciation. Based on the results, it is possible to conclude that both explicit and implicit WCF is effective in the similar EFL context. However, effectiveness of WCF is not merely a matter of feedback type, but interplay of affective, cognitive, behavioral engagement and learners’ perceptions. These findings imply that pedagogical practitioners should conceptualize WCF not merely as an instrument for error correction, but as a multifaceted cognitive catalyst. Consequently, teachers in similar EFL contexts are advised to strategically integrate both feedback types to balance immediate mechanical accuracy with the promotion of long-term metacognitive development, thereby addressing the nuanced relationship between pedagogical interventions, student engagement, and writing quality