Preheat the oven to 350 degrees F. Line a muffin pan with liners and set aside.
In a medium bowl, whisk together the flour, cinnamon, baking soda, baking powder, and salt.
Make a well (hole) in the center of the flour mixture and add in the mashed banana, eggs, honey, vanilla extract, and melted butter. Mix together until well combined. Fold in the walnuts. Do not over mix.
Pour the batter into the muffin pan. Bake until golden brown, about 18 – 20 minutes.
Store at room temperature or to freeze: after the cooked muffins have completely cooled, put them in an airtight container or bag to freeze. When you are ready to defrost, just place them in the fridge overnight.