Oven rack placed in the center, pre-heat the oven to 350°F. Lightly grease a 9"x 5" loaf pan and set to the side
In a large bowl, stir together the mashed banana, oil, sugar, eggs, and vanilla. Set aside
In a separate bowl, whisk the flours, oats, baking soda, baking powder, salt, cinnamon till evenly combined.
Mix the dry ingredients into the banana mixture, making sure to scrape the bottom and sides of the bowl. Once the batter it fully incorporated, fold in the flax seeds and walnuts
Pour the batter into prepared baking dish and evenly sprinkle remaining sugar over the top before baking.
Option to sprinkle some extra oats and seeds on the top, along with the sugar
Bake for about 75 minutes or until golden and feels firm to a light touch. To be confident its cooked through, using a thin knife, insert it into the center and if it comes out clean, or with just a few moist crumbs (but no wet batter) your bread is done. If the bread seems to be browning too quickly, tent it with aluminum foil for the final 15 to 20 minutes of baking.
Side Note: If baking in a glass pan, increase the baking time by 15 to 20 minutes and drop the temp to 325°F
Once finished, remove the bread from the oven and let it cool it in the pan for 15 minutes. Using a knife, loosen the edges and turn it out onto a rack to cool completely. Do not cut or package until fully cooled!
It may be tempting to tear off a chunk, but I promise the wait it well worth it!