Preparation Steps

• Heat your oven to 350°F (177°C). Grease a 9x5-inch loaf pan, line with a strip of parchment if you like for easy removal, and lightly dust the pan with flour or tap out excess.
• Spread the walnuts on a small baking sheet and toast in the oven for 6–8 minutes until fragrant. Let cool, then chop coarsely. Reserve a tablespoon or two for sprinkling on top.
• In a medium bowl combine the flours, baking soda, salt, and cinnamon. Whisk together so the leavening and spices are evenly distributed.
• In a large mixing bowl mash the bananas with a fork until mostly smooth. Stir in the brown sugar, melted butter, eggs, Greek yogurt, and vanilla until the mixture is homogeneous.
• Add the dry ingredients to the banana mixture and fold everything together gently with a spatula or wooden spoon. Mix just until no large streaks of flour remain — overmixing will make the loaf dense.
• Fold in the toasted walnuts, keeping a small handful back for the top. Let the batter rest for 8–10 minutes; this short rest lets the flours hydrate and improves the crumb.
• Spoon the batter into the prepared pan, smoothing the top with a spatula. Scatter the reserved walnuts over the surface and gently press them in.
• Bake at 350°F (177°C) for 50–60 minutes, checking at 50 minutes. The bread is done when the center springs back lightly and a toothpick inserted into the middle comes out with a few moist crumbs (not raw batter). If the top browns too fast, tent loosely with foil.
• Cool the loaf in the pan on a wire rack for about 10 minutes, then transfer the bread to the rack to cool completely before slicing. Cooling fully helps the texture set so you get neat slices.