First, preheat oven to 350ºF and spray a nonstick muffin tin with nonstick cooking spray. Alternatively, line with muffin liners.
In a large bowl, mash 3 large bananas. Then, add all wet ingredients minus the coconut oil. Whisk until combined.
In a separate bowl, combine dry ingredients together (except for walnuts).
Slowly add dry ingredients to wet and mix.
Finally, add walnuts and melted coconut oil, and mix well.
Spoon batter into muffin til, filling 3/4 of the way full. Option to sprinkle on additional walnuts to the top.
Bake at 350ºF for 19-22 minutes.
Remove from oven once fully cooked and let cool for 5 minutes, and remove from pan to finish cooling.
Enjoy!