Ingredients
Equipment
Method
Prep the pan and oven
- Preheat the oven to 350°F, then grease and line a 9×5-inch loaf pan with parchment paper to prevent sticking.
Mix the wet ingredients
- Beat the softened butter and granulated sugar for 2–3 minutes until light and fluffy, scraping the bowl as needed to keep the texture even.
- Add the eggs one at a time, beating well after each addition until fully incorporated.
- Mix in the vanilla extract until smooth and evenly combined.
- Stir in the mashed bananas and sour cream until smooth with no streaks remaining.
Combine the dry ingredients
- Whisk together the all-purpose flour, baking soda, and kosher salt until the leavening and salt are evenly dispersed.
- Fold the dry ingredients into the banana mixture until just combined, keeping the batter thick and avoiding overmixing to protect tenderness.
Add walnuts and bake
- Fold in the toasted walnuts, distributing them evenly throughout the batter so every slice has some crunch.
- Pour the batter into the prepared loaf pan and sprinkle the top with coarse sugar if using for a lightly sparkling crust.
- Bake at 350°F for 60–70 minutes, until a toothpick inserted into the center comes out clean and the loaf is golden brown.
Cool and slice
- Cool the bread in the pan for 15 minutes so it sets, then transfer it to a wire rack to cool completely before slicing.
Notes
For the best crumb, use very ripe bananas and mix the batter only until the dry ingredients disappear—overmixing can make quick bread tougher. Store tightly wrapped at room temperature for up to 3 days or refrigerate up to 5 days. Freeze for up to 2 months (slice after fully cooled). Dietary swap: for a dairy-free option, use a 1:1 plant-based butter and sour-cream substitute, keeping the same mixing and bake times.