The purpose of this study was to bake sweet rice muffins with oak mushroom (Lentinus edodes) powder. The process included substituting sweet rice flour for cake flour and adding oak mushroom powder. This study determined the optimal mixing conditions of oak mushroom muffins by adjusting the amounts of oak mushroom powder, whole eggs, and soybean oil. The mixing conditions for the oak mushroom muffins included 3 categories: oak mushroom powder (X1), whole eggs (X2), and soybean oil (X3) by Central Composite Design (CCD) which was optimized by Response Surface Methodology (RSM). Oak mushroom muffin formulation was optimized using rheology. Yellowness (p〈0.001) and redness (p〈0.05) displayed a linear model pattern, whereas lightness (p〈0.05) was represented by a quadratic model. Among the sensory properties, variables that appeared to show significant values such as appearance (p〈0.5), texture (p〈0.5), and overall quality (p〈0.5) were used to identify optimums. The result of mechanical properties showed significant values in gumminess (p〈0.5) and chewiness (p〈0.5). The numerical and graphical methods used in this study determined that the optimum formulation for oak mushroom powder sweet rice muffins was 8.75 g of oak mushroom powder, 235.95 g of whole eggs, and 19.93 g of soybean oil.