Preheat your oven to 325° and grease 2 standard loaf pans.
In a mixing bowl, measure and the flour, baking powder, baking soda, cinnamon and nutmeg. Whisk to combine, and then setting off to the side.
Then in separate bowl, mash the bananas with a fork. Set this aside for a moment as well.
Next, on a larger mixing bowl (or in the bowl of your stand mixer, fitted with the paddle attachment) add the softened butter with both sugars. Mix on medium-low speed until light and creamy.
To the same bowl, add the mashed bananas, eggs, milk, vanilla extract and kosher salt. Mix on low to medium-low until combined.
Gradually add 1/3 of the flour mixture at a time, mixing until incorporated. With a rubber spatula, scrape down the sides and bottom of the bowl to insure all the ingredients are incorporated.
Divide the batter (about 1-1/2 cups each) among the prepared pans and spread evenly. Use any extra ripe bananas by cutting it in half and placing one on top of each loaf. If you have two leftover bananas you can stagger the halves on each loaf.
Place both pans on the middle rack of your preheated oven and bake for 35 to 40 minutes or until a tester, inserted into the middle, comes out clean and/or with a few crumbs still attached. If there’s any trace of batter, place the pan or pans back into the oven and bake for 2 minutes more or until done.
Allow the banana bread to cool in the pans for 10 to 20 minutes before removing and placing on a wire rack to finish cooling.
Slice and serve with softened salted butter.