This study explored the potential of banana flower powder (BFP) as a nutritional ingredient in muffins by assessing its impact on physicochemical properties, bioactive contents, and sensory preference. BFP contained high levels of protein (20.54 g/100 g dry weight (DW)), crude fiber (28.57 g/100 g DW), and antioxidant compounds, including total phenolic content of 2,564 mg gallic acid equivalent/100 g DW, total flavonoid content of 164.6 mg rutin equivalent/100 g DW, and total anthocyanin content of 2,729 µg cyanidin 3-glucoside equivalent/100 g DW. Incorporating BFP into wheat flour (5–25% substitution, w/w) significantly altered the pasting behavior of composite flours, characterized by increased gelatinization temperature (57.4–58.1°C), and reduced peak viscosity (926–875 Brabender units (BU)) and final viscosity (1,084–956 BU) compared to wheat flour (57.3°C, 1,021 BU and 1,188 BU, respectively). These modifications suggested limited starch swelling and disrupted gluten network formation, which translated into notable changes in muffin texture, specifically, increased hardness and chewiness, and reduced cohesiveness. Microstructural analysis supported these findings, revealing denser crumb structures of muffins with BFP leading to a lower specific volume (from 1.85 to 1.71 mL/g compared to 2.09 mL/g for control muffins) and porosity (from 39.32 to 32.93% compared to 43.72% for control muffins). Although crumb color darkened with increasing BFP levels, sensory evaluation showed that muffins with up to 15% substitution of wheat flour by BFP (w/w) maintained high acceptability in terms of appearance, texture, and taste with the scores of >7.6 over 9.0. The findings demonstrated that BFP could be effectively utilized to produce nutrient-dense muffins while maintaining acceptable sensory quality, particularly texture, requires careful optimization of the BFP content within a specified threshold.