We added banana flavor without introducing too much moisture to our banana bread recipe by microwaving the fruit and draining it. We then simmered the banana liquid in a saucepan until it reduced and incorporated it into the batter. We used brown sugar instead of granulated and swapped out oil for the nutty richness of butter. Toasted walnuts gave our banana bread recipe a pleasing crunch, and a sixth banana sliced thin and caramelized on top of the loaf gave our banana bread an enticingly crisp, crunchy top.

We added banana flavor without introducing too much moisture to our banana bread recipe by microwaving the fruit and draining it. We then simmered the banana liquid in a saucepan until it reduced and incorporated it into the batter. We used brown sugar instead of granulated and swapped out oil for the nutty richness of butter. Toasted walnuts gave our banana bread recipe a pleasing crunch, and a sixth banana sliced thin and caramelized on top of the loaf gave our banana bread an enticingly crisp, crunchy top.

• 1 3/4 cups (8 3/4 ounces) unbleached all-purpose flour
• 1 teaspoon baking soda
• 1/2 teaspoon table salt
• 6 large very ripe bananas (about 2 1/4 pounds), peeled (see note)
• 8 tablespoons (1 stick) unsalted butter, melted and cooled slightly
• 2 large eggs
• 3/4 cup (5 1/4 ounces) packed light brown sugar
• 1 teaspoon vanilla extract
• 1/2 cup walnuts, toasted and coarsely chopped (optional)
• 2 teaspoons granulated sugar

1. Adjust oven rack to middle position and heat oven to 350 degrees. Spray 8½ by 4½-inch loaf pan with nonstick cooking spray. Whisk flour, baking soda, and salt together in large bowl.
2. Place 5 bananas in microwave-safe bowl; cover with plastic wrap and cut several steam vents in plastic with paring knife. Microwave on high power until bananas are soft and have released liquid, about 5 minutes. Transfer bananas to fine-mesh strainer placed over medium bowl and allow to drain, stirring occasionally, 15 minutes (you should have ½ to ¾ cup liquid).
3. Transfer liquid to medium saucepan and cook over medium-high heat until reduced to ¼ cup, about 5 minutes. Remove pan from heat, stir reduced liquid into bananas, and mash with potato masher until fairly smooth. Whisk in butter, eggs, brown sugar, and vanilla.
4. Pour banana mixture into flour mixture and stir until just combined with some streaks of flour remaining. Gently fold in walnuts, if using. Scrape batter into prepared pan. Slice remaining banana diagonally into ¼-inch-thick slices. Shingle banana slices on top of either side of loaf, leaving 1½-inch-wide space down center to ensure even rise. Sprinkle granulated sugar evenly over loaf.
5. Bake until toothpick inserted in center of loaf comes out clean, 55 to 75 minutes. Cool bread in pan on wire rack 15 minutes, then remove loaf from pan and continue to cool on wire rack. Serve warm or at room temperature.

Don’t even think of making banana bread with anything less than very ripe, heavily speckled fruit—unless you’re fine with a bland loaf. As bananas ripen, their starch converts to sugar at an exponential rate. In lab tests, we found heavily speckled bananas had nearly three times the amount of fructose (the sweetest of the sugars in fruit) than less spotty bananas. (The exact percentage will vary from fruit to fruit.) But the impact of ripeness only goes so far: We found little difference in sweetness between loaves baked with completely black bananas and those made with heavily speckled ones.

TOO SOON 1.8% FRUCTOSE - A lightly speckled banana has only a little fructose, the sweetest sugar in fruit.

JUST RIGHT 5.3% FRUCTOSE - A heavily speckled banana has a lot more fructose.