Preheat the oven to 350°F (177°C). Spray a 9x5 inch loaf pan with cooking spray or line with parchment paper. Set aside.
In a large bowl, whisk together the flour, baking powder, baking soda and salt. Set aside.
In a medium bowl, mash the bananas (you can use a fork, or a pastry blender). Whisk in the brown sugar, melted butter, eggs and bourbon. Mix well.
Make a well in the middle of the flour mixture and add the banana mixture to it. With a wooden spoon or spatula, stir until just combined. Do not overmix.
Fold in the pecans.
Transfer the batter to the prepared pan and bake for 50-55 minutes or until a toothpick comes out cleanly or with a few moist crumbs clinging to it. If there is any wet batter, continue baking. (if using a glass pan, you will need an additional 5 minutes) Cool in the pan for 15 minutes before transferring to a cooling rack.
While the bread is cooling, make the glaze. In a small saucepan and melt the butter on medium heat. Bring to a boil and cook until the butter turns a golden color, about 10 minutes. Keep an eye on the butter so it doesn’t burn. Remove from heat.
In a small bowl, stir together the powdered sugar, maple syrup, vanilla extract and browned butter. Whisk together. It will be quite clumpy.
Add the Kentucky bourbon and whisk together until smooth and the consistency of pancake batter.
Drizzle the glaze over the cooled loaf. Slice and serve!