Bananas continue to experience high post-harvest losses of up to 45% due to limited value addition. The limiting factor being lack of key nutrients in the fruit hence the need to supplement banana with different ingredients. The purpose of this study was to evaluate the effect of changing ingredient type and concentration on functional properties and analyze the potential of developing an acceptable soup for children between 6 to 59 months using banana flour. Using Nutri-survey, grain amaranth, pumpkins, tomatoes, mushrooms and carrots were the selected ingredients. Design Expert was used to perform Response surface methodology (RSM) using a mixture design to establish the optimal ingredient concentrations. The optimal formulation constituted banana, grain amaranth, pumpkins, carrots and mushrooms at 41%, 41%, 9%, 5% and 4% respectively. Tomatoes were eliminated for its insignificant effect (p<0.05) to functional properties of the soup flour. The product had an energy composition of 409.39 kCal/100 g, peak viscosity of 2631.41 Cp while the holding viscosity, breakdown viscosity, final viscosity, peak time, carbohydrates, proteins and zinc contents were 1430.11 Cp, 1209.57 Cp, 2495.29 Cp, 4.9 minutes, 65.38%, 14.86% and 13.50 g/100 g respectively. Mathematical models predicting variation of gross energy, protein content, fiber content and ash content were significant at p<0.05. The results suggest that a nutritious soup can be obtained from banana flour.