1Preheat the oven to 175C. Line a loaf pan with parchment paper. Spray the bottom with nonstick spray or with some oil.
2Make the brown butter. In a small pan, melt the butter over medium heat. Whisking frequently until the butter begins to brown and smells really nutty. Remove the browned butter from the pan, and pour into a heatproof bowl, allow to cool for 15 minutes. If you are using veg oil, you can skip this part.
3Mash banana in a large bowl. Add egg, sugar and the browned butter, or oil, if using. Stir to combine.
4Add the plain flour, baking soda and salt. Mix till well combined.
5Add chocolate chips and mix again.
6Pour the batter into a loaf pan lined with parchment paper.
7Top with more chocolate chips, if you want.
8Bake at 175C for 50-60 minutes, or until toothpick comes out clean.