Preheat the oven to 350 °F (175 °C). Line a 9x5-inch (23x13 cm) loaf pan with parchment paper, leaving some overhang for easy removal.
Spread the walnuts on a baking sheet and toast for 8-10 minutes, stirring once, until fragrant. Let cool, then chop coarsely. Reserve 1/4 cup (30 grams) of the chopped walnuts for the top of the loaf. You can chop these a little more finely, if desired.
1 cup walnuts
In a medium bowl, whisk together the whole wheat flour, cinnamon, baking soda, baking powder and salt.
1 1/2 cups whole wheat flour, 2 teaspoons ground cinnamon, 1 teaspoon baking soda, 1/2 teaspoon baking powder, 1/2 teaspoon salt
In another medium bowl, whisk together the brown sugar, eggs, honey, oil and vanilla. Stir in the mashed bananas.
1/2 cup brown sugar, 2 large eggs, 1/4 cup honey, 3 tablespoons canola, vegetable or light olive oil, 1 teaspoon vanilla extract, 480 grams mashed banana
Add the wet ingredients to the dry ingredients and stir just until combined. Do not overmix.
Fold in the remaining 3/4 cup (90 grams) of chopped walnuts.
0.75 cup walnuts
Pour the batter into the prepared loaf pan and smooth the top. Sprinkle the reserved walnuts evenly over the batter.
0.25 cup walnuts
Bake for 45-55 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs. The exact baking time can vary depending on how ripe and moist the bananas are.
Let the bread cool in the pan on a wire rack for 15 minutes. Remove from the pan and let cool completely on the rack before slicing.
Store in an airtight container at room temperature for up to 5 days. To freeze, wrap the cooled bread or individual slices tightly and freeze in a freezer-safe container or bag for up to 3 months.