Preheat your oven to 350°F and position a rack in the center. Grease a 9x5 inch loaf pan or line it with parchment paper for easy removal. Mash your bananas until completely smooth—this ensures even moisture distribution throughout the bread. Chop your walnuts into roughly 1/4-inch pieces and set aside. Having everything prepped before you start mixing is key to avoiding overmixing the batter once the wet and dry ingredients combine.

In a large mixing bowl, whisk together the flour, both sugars, baking soda, salt, and ground nutmeg until evenly combined. This ensures the leavening agent is distributed throughout and prevents dense pockets in your finished bread. Set this bowl aside—you'll combine it with the wet ingredients shortly.

In a separate bowl, whisk together the mashed bananas, eggs, Greek yogurt, oil, and vanilla until smooth and fully incorporated. I prefer using Fage 5% Greek yogurt for its richness and tangy flavor—it adds moisture while keeping the bread tender. The room temperature eggs will emulsify better with the other ingredients, creating a more cohesive batter.

Pour the wet ingredient mixture into the dry ingredients and gently fold together using a spatula or wooden spoon until just combined. Stop mixing as soon as you no longer see dry flour streaks—overmixing develops gluten and makes banana bread tough and dense. A few small lumps are perfectly fine and actually desirable.

Fold the chopped walnuts into the batter using just a few gentle strokes, then immediately pour the batter into your prepared loaf pan. Spread it evenly and smooth the top with a spatula. Getting the batter into the oven quickly after combining prevents any additional gluten development.

Bake at 350°F for 50-60 minutes, until a toothpick inserted into the center comes out with just a few moist crumbs (not wet batter). The bread is done when the top is golden brown and the sides have slightly pulled away from the pan. Baking times vary by oven, so start checking around the 50-minute mark.

Allow the banana bread to cool in the pan for about 15 minutes, then turn it out onto a wire rack to cool completely before slicing. This resting period lets the crumb set up so it slices cleanly rather than crumbling. Serve at room temperature or slightly warm with butter if desired.