Preheat oven to 400℉ and line a 9x5 loaf pan with parchment paper.
In a small saucepan, melt butter over medium heat.
Add milk powder. Continue cooking, whisking constantly, until golden brown.
Add sugar to browned butter mixture and whisk until smooth. Turn off heat and set aside.
In a large bowl, mash bananas until smooth. A couple small chunks is okay.
Add eggs and vanilla and whisk until smooth.
Add the butter mixture and whisk until smooth.
Add the flour, baking soda, cinnamon and salt. Fold with a rubber spatula until just combined.
Add the chocolate chips and fold until just combined.
Pour batter into the prepared loaf pan.
Bake for 10 minutes. Then lower the oven temperature to 325℉ for 40-50 minutes, or until a toothpick poked in the center of the loaf comes out clean. Make sure to poke all the way to the bottom of the pan, as the loaf is quite tall and the top will appear done even if the center isn't fully baked.