Step 1

Heat the oven to 350°F with a rack in the upper-middle position. Mist a 9-by-5-inch loaf pan with cooking spray. In a large bowl, whisk together the flour, baking powder, baking soda and salt.

Step 2

In a medium saucepan over medium heat, melt the butter. Once melted, continue to cook, swirling the pan often, until the butter is fragrant and deep brown, 2 to 3 minutes. Remove the pan from the heat and immediately whisk in the cardamom.

Step 3

Carefully add the bananas (the butter will sizzle and bubble up) and whisk until combined. Add the brown sugar, eggs and vanilla, then whisk until smooth. Add the banana mixture to the flour mixture and, using a silicone spatula, fold until just combined and no dry flour remains.

Step 4

Transfer the batter to the prepared pan and sprinkle evenly with the white sugar, if using. Bake until the loaf is well browned, the top is cracked and a toothpick inserted at the center of the loaf comes out clean, 50 to 55 minutes, rotating the pan halfway through. Cool the bread in the pan on a wire rack for 15 minutes, then turn out the loaf and cool completely before serving. Cooled bread can be wrapped tightly and stored at room temperature for up to 4 days or refrigerated for up to 1 week.