03While the butter is browning, combine the ingredients for the crumb topping in a medium bowl (use your hands or a fork to mix the 2 Tablespoons of cold) butter into the dry topping ingredients until crumbly, pea-sized crumbs form). Set aside.
04Back to the bread… In a medium bowl, whisk together the flour, salt, baking soda, and cinnamon, and set aside.
05In the bowl of your mixer, combine the egg and sugar, and mix at medium speed until light and fluffy.
06Mix in the cooled brown butter slowly.
07Add the mashed bananas, the milk and the vanilla extract, and mix on medium speed until combined.
08Mix in the flour mixture until combined.
09Pour the batter into the prepared loaf pan. Sprinkle the crumb topping evenly over the top of the batter.
10Bake for about 1 hour, or until a toothpick inserted in the center comes out clean. Let cool before enjoying!