Preheat oven to 350° F. Spray a 9x5-inch loaf pan with cooking spray. Lay a sheet of parchment paper across the bottom and up the sides of the pan (see photo in post above).
Melt the butter in a large glass bowl in the microwave (or melt butter in a pot on the stove and transfer to a large mixing bowl).
5 tablespoons (71g) unsalted butter
Add the honey and mashed banana to the bowl and whisk to combine. Whisk in the eggs.
½ cup (168g) honey, 1 ¾ cups (395g) mashed ripe banana, 2 large eggs
Add the baking soda, salt, cinnamon and vanilla to the bowl. Whisk until very well combined.
1 teaspoon baking soda, ½ teaspoon salt, ½ teaspoon ground cinnamon, 1 teaspoon vanilla extract
Add the flour and mix with a rubber spatula until just combined. You want all of the flour to be incorporated into the batter, but try not to over-mix.
2 cups (240 grams) white whole wheat flour
Transfer the batter to the prepared baking pan. Bake for 55-65 minutes, until a toothpick inserted into the center of the loaf comes out clean. Check on the banana bread after 35 minutes and loosely cover with foil as needed to prevent the top from over-browning.
Let the bread cool in the pan for 10 minutes and then transfer it to a wire rack to finish cooling.