My friend Shaw makes fabulous banana bread. His secret? Lots and lots of bananas--the ripest, blackest, grossest, most alarming-looking bananas possible. Not only does this make the bread flavorful and moist, it also means you can cut way back on the added sugar, because the bananas are so sweet themselves. This is my version of Shaw's bread, and it's sticky and squishy and wonderful. —ieatthepeach
Preheat oven to 350º F. Grease and flour a 9×5 loaf pan, or line the pan with parchment paper. In a medium mixing bowl, whisk together whole wheat flour, all-purpose flour, baking soda, and salt. Set aside.
Place bananas in a large mixing bowl, and use a potato masher or fork to mash into a chunky paste. Add honey or maple syrup, oil, egg, and vanilla, and mix until combined but still chunky. Add dry ingredients and mix until just combined–a few streaks of flour are fine. Fold in walnuts (if using).
Transfer batter to the prepared loaf pan, and even out the top. Bake for 1 hour, or until a toothpick inserted in the center comes out clean. Remove from the oven and transfer pan to a cooling rack. Let the bread cool in the pan for 10 minutes, then turn out onto the rack to finish cooling. Slice and serve just warm or at room temperature.
To store leftover banana bread, wrap the loaf or individual slices in a layer of plastic wrap, then in aluminum foil. Wrapped this way, the bread will keep in the refrigerator for up to 1 week, or in the freezer for up to 2 months.