1Brown the butter on a stovetop, then immediately remove it from the heat to prevent burning and add to a large bowl.
2Mash the ripe bananas until they are mushy.
3Add milk, mashed bananas, and vanilla bean paste to the bowl with the brown butter.
4Add the banana bread mix to the wet ingredients and mix until just combined, being careful not to overmix.
5In a separate container (a small plastic bag), mix the chocolate chips with flour.
6Fold the flour-coated chocolate chips into the batter.
7Butter a loaf pan and pour the batter into it.
8Sprinkle the top of the batter with additional chocolate chips and flaky sea salt.
9Bake in a preheated oven at 350°F (175°C) for 50-55 minutes, or until the top is brown and crispy and a toothpick inserted into the center comes out clean.
10Let the banana bread cool completely before slicing and serving.