Melt the butter in a pan on medium heat. Butter will start foaming and crackling. Swirl the pan as the crackling subsides. At this stage the butter will start changing color to brown and smell nutty. Switch off the flame and transfer butter to a large mixing bowl. Let it cool.
Pre-heat oven to 175 degree Celsius. Grease an 8X5 inch loaf tin with butter and line with parchment paper in such a way that the parchment paper hangs over the edges. This will help you lift out the banana bread easily once its baked.
You can pop some walnuts, whatever it is you are using, in the oven for 10 minutes while it's preheating to roast them. Once roasted, chop them up and keep aside. Keep a timer though because they can burn easily.
Once the butter has cooled, add sugar and mix. Add eggs one at a time, mixing after each egg till everything has combined. Add the milk and vanilla extract to this mixture, and give it another whisk.
Peel the bananas and mash them into the mixture. I like my bread chunky but you can mash the bananas completely if you like.
Sift flour, baking soda and salt into the bowl with the banana mixture, and fold till everything is combined. There is no need to blend or over mix. Add the nuts and mix. Sprinkle with a little sugar (This gives an amazing crunchy crust to the bread).
Tap once to get rid of air bubbles, and place pan in the oven. Bake for 50 to 60 minutes. Start checking for done-ness around 50 minutes. A skewer or fork inserted into the middle should come out clean.
Once done, let the bread cool in the pan for 8-10 minutes. Lift the bread using parchment paper and let it cool on a wire rack for another 10 minutes. Or slice it immediately, like I did.