Demak is an area in Indonesia with a high stunting rate of 50.28%. Mangrove fruit, a major regional commodity, should be used as a basis for Supplementary Feeding Program (SFP) cookies to overcome stunting in Demak. This study was aimed to analyse the nutritional content, nutrition absorption inhibiting agents, and acceptance of mangrove fruit cookies. This research used a completely randomized sample with a one-factor design to formulate mangrove and soybean flour. The formulations used were F1 (60%: 40%), F2 (70%: 30%), F3 (80%: 20%), and F0 (100% wheat flour) as the control group. The best formula of mangrove and soybean cookies was F2 with average energy 479.44 kcal/100 g, protein 11.70 g/100 g, fat 23.93 g/100 g, carbohydrate 54.31 g/100 g, zinc 2.68 mg/100 g, iron 6.72 mg/100 g, calcium 659.03 mg/100 g, HCN 1.77 ppm, and tannin 101.9 mg/100 g. The best cookie formulation that met the SFP quality requirements was F2, with a composition of 70% mangrove fruit flour and 30% soy flour.