Preheat your oven to 375°F (190°C). Lightly grease the top surface of a 12-cup muffin tin with cooking spray to prevent sticking. Insert muffin liners if desired.

In a large mixing bowl, whisk together the all-purpose flour, baking soda, and salt until well combined. Set aside.

In a separate mixing bowl, mash the overripe bananas thoroughly using a fork until smooth. Add the brown sugar and beat with an electric mixer on medium speed for approximately 3 minutes until light and well blended.

Add the melted and cooled butter to the banana mixture, followed by the eggs and vanilla extract. Mix well until fully incorporated, scraping down the sides of the bowl as needed.

Gradually stir the dry ingredients into the wet mixture. Mix until just about halfway combined—some visible streaks of flour are fine at this stage.

Add the chopped pecans and gently fold the mixture by hand until all dry ingredients are fully incorporated. Avoid overmixing to maintain a tender crumb.

Spoon the batter evenly into the prepared muffin tin, filling each cup approximately halfway. Tap the muffin pan lightly on the counter to release any air bubbles.

Bake for 18 to 20 minutes, or until a toothpick inserted into the center of a muffin comes out clean or with a few moist crumbs. Allow the muffins to cool in the pan for a few minutes before transferring them to a wire rack.