Preheat oven to 350°F.Spray a standard muffin tin with non-stick cooking spray and set aside.
Add the mashedbananas, melted butter, and milk to a large mixing bowl. Mix to combine.
Beat in the egg andvanilla, and brown sugar.
Add in the remaining dryingredients and fold in until just mixed. Then, fold in the walnuts.
Fill muffin pan cupsto about 4/5 full. Top with additional walnuts, if desired.
Placein the pre-heated oven and bake for 18-20 minutes, or until toothpick insertedin the center of a muffin comes out clean. Remove from oven and cool for atleast 5-10 minutes before serving. Enjoy!