Preheat oven to 350°F (175°C). Grease or line a 9×5 loaf pan.
In a medium bowl, whisk together the fresh milled flour, baking soda, baking powder, salt, and cinnamon.
In a separate large bowl, mix the eggs, butter, brown sugar, and vanilla until smooth.
Stir in the mashed bananas until fully combined.
Add the dry ingredients to the wet ingredients and gently mix until just combined.
Stir in the milk (or substitute) until the batter is smooth. Do not overmix.
Pour batter into the prepared loaf pan.
Bake for 55–65 minutes, or until a toothpick inserted into the center comes out clean.
Allow to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.