This study was aimed to improve nutritional, functional and consumer safety aspects of cabbage powder (CP). White cabbage (Brassica oleracea var. capitata f. alba) was dehydrated to CP following microwave heating, blanching, alkali or acid washing treatments. The results for nutrients and mineral composition of raw and processed CP elucidated raw CP to exhibit significantly (p < 0.05) higher amounts of protein (12.2%), dietary fiber (25.2%), Na (52 mg/100 g), Ca (355 mg/100 g), K (286 mg/100 g), Fe (14 mg/100 g) and Zn (32 mg/100 g). Among different processing techniques, microwave treatment resulted in a higher rate of reduction for alkaloids, oxalates, tannins and phytates contents, i.e., 77%, 85%, 85%, and 86%, respectively. Likewise, microwave treatment was found more effective in reducing residual levels of neonicotinoids, pyrethroids, organophosphates including imidacloprid, cypermethrin, bifenthrin, chlorpyrifos and deltamethrin in cabbage in the range of 0.98–0.12 ppm, 1.22–0.23 ppm, 1.03–0.15 ppm, 1.97–0.43 ppm, and 2.12–0.36 ppm, respectively. CP supplementation at the rate of 5% in unleavened flatbreads was observed to maintain textural and sensory attributes of the product. The results suggest microwave heating as a cost-effective technique to reduce toxicants load in cabbage powder. Further, ~5% supplementation of CP in wheat flour may also improve nutritional and functional properties of the baked goods.