COVID-19 pandemic has increased the demand for antioxidant and micronutrient-rich foods that are easy to prepare, consume, and require less handling. In this research, we worked on the development of nutritious extruded snack made from barnyard millet, defatted soy flour, Indian gooseberry powder, and rice flour. Box–Behnken Design of Response Surface Methodology was utilized to determine the influence of process variables viz; blend ratio of barnyard millet and defatted soy flour, extruder barrel temperature, and Indian gooseberry powder on nutritional and organoleptic properties of snack. Optimized extruded snack were attained at blend ratio (6:1), barrel temperature (115°C), and Indian gooseberry (12.25 g/100 g of total flour). Extruded snack presented good overall acceptability along with high fiber (16.84 g/100 g), protein (18.91 g/100 g), total phenol (67.51 mg GAE/100 g), and total flavonoid (153.61 mg RE/100 g) content. Microbial analysis indicates that extruded snack can be stored for up to 60 days without microbial contamination. Novelty impact statement The pandemic has made people refocus on the foods that are nutritious, yet take less time to prepare and handle. In the present research, we explored the use of locally available and low-cost barnyard millet and defatted soy flour coupled with Indian gooseberry powder—a rich source of antioxidants and rice flour for the preparation of nutritious snack. Extrudates developed with a higher blend ratio at higher barrel temperature and enriched with Indian gooseberry content displayed excellent nutritional, bioactive, and dimensional characteristics. The study will help formulate extruded snack with high protein, antioxidants, as well as fiber content.