Begin by browning your butter. In a light-colored saucepan over medium heat, melt the butter. Continue to cook, swirling occasionally, until it turns a deep amber color and smells nutty. This should take about 5-7 minutes. Immediately pour the brown butter into a heatproof bowl to stop the cooking and let it cool slightly.
Preheat your oven to 350°F (175°C). Grease and flour a 9x5 inch loaf pan, or line it with parchment paper.
In a medium bowl, whisk together the flour, baking soda, salt, cinnamon, nutmeg, and cloves. Set aside.
In a large bowl (or the bowl of your stand mixer), combine the mashed bananas and the slightly cooled brown butter. Beat until well combined.
Add the brown sugar, eggs, and vanilla extract to the banana mixture. Beat until smooth and fully incorporated.
Gradually add the dry ingredients to the wet ingredients, mixing on low speed (or with a spatula) until just combined. Be careful not to overmix.
Gently fold in the toasted chopped pecans.
Pour the batter into the prepared loaf pan and spread evenly.
Bake for 50-65 minutes, or until a wooden skewer inserted into the center comes out clean. If the top starts to brown too quickly, you can loosely tent it with aluminum foil.
Let the banana bread cool in the pan for 10-15 minutes before inverting it onto a wire cooling rack to cool completely.