Preheat oven to 400°. Spray large muffin pan with cooking spray (I used coconut oil), or line with baking liners.
Whisk together flour, baking powder, baking soda, cinnamon and salt in a large mixing bowl and set aside.
In a medium bowl, mix melted coconut oil, milk, sugar, brown sugar, and vanilla together until blended. Stir in bananas.
Fold wet ingredients in to dry ingredients and mix with a spatula just until combined.
Add chopped walnuts.
Fill large muffin pan ¾ full and bake for 20-25 minutes or until wooded tooth pick inserted comes out clean.
Cool on a cooling rack for 10 minutes.
Enjoy!