Preheat oven to 350F

Line a baking sheet with foil and arrange the bananas on it. Bake for 30 minutes. The bananas will get black and oozy. Let them cool for 15 minutes, then peel and mash the bananas. I did this in my food processor, just pulsing till they were broken down, but you can do it by hand. Set aside. You should have about 2 cups. I had a little extra and I threw it all in :) You can never have enough banana!

Turn the oven down to 325F Lightly grease and line 2 standard 9x5 loaf pans with parchment. The parchment should have long ends hanging off the sides so you can lift the bread out later for slicing.

Whisk together the flour, baking powder, baking soda, and salt.

In a separate bowl whisk the mashed bananas, buttermilk, vanilla, and lemon juice.

Cream the butter in a stand mixer, on high, for 3 minutes. Scrape down the sides and add the sugar to the mixer, beat on high for another 5-7 minutes, scraping down the sides of the bowl as necessary until the mixture is light and fluffy.

Beat in the eggs, one at a time, on low, scraping down the bowl as needed to get everything incorporated. Beat in the wet ingredients, just until fully blended. Then add the flour and mix just until combined with no white flour remaining.

With the mixer on low, fold in the walnuts. Remove the bowl from the mixer and finish by hand with a silicone spoonula or spatula, taking care to get any unmixed ingredients from the bottom of the bowl.

Turn the batter into the two prepared loaf pans and spread out evenly. Bake for 60 to 70 minutes, or until the breads are risen, slightly golden, and a toothpick inserted in the center comes out without wet batter on it.

While the bread is hot from the oven, brush with the melted butter and sprinkle liberally with sugar. Let cool for 15 minutes, and then remove the bread from the pans to cool further.