Whisk the dry ingredients together in a medium bowl.
Set aside.
In the bowl of your stand mixer, mash the bananas.
Beat in the melted browned butter, brown sugar, egg, vanilla extract, and milk on medium speed.
Add the dry ingredients to the butter mixture, then beat on low just until combined.
Fold in the nuts.
Spoon the batter into liners, filling them to the top.
Bake for 5 minutes at 425°F, then reduce the oven temperature to 350°F.
Bake for an additional 10-15 minutes or until an instant-read thermometer registers 200F when poked in the center of a muffin or a toothpick comes out with just a few moist crumbs sticking to it. Don't overbake.
Allow the muffins to cool for 5 minutes in the muffin pan, then transfer to a wire rack to cool completely.
Notes
Storage:Store leftover brown butter banana pecan muffins in an airtight container at room temperature for up to three days. You can also freeze ‘em in a freezer-safe bag for up to three months.Tips:
Use overripe bananas. The browner and spottier they are, the softer and sweeter your muffins will be.
Muffins are done when the interior temperature registers 200F on an instant read thermometer.
Stir the batter just until the flour disappears for tender, fluffy muffins. Overmixing flour can make the muffins tough.