Preheat oven to 350ºF and prepare a standard 9x5 loaf pan with cooking spray and parchment paper.
In a large bowl, mix the mashed bananas, melted butter, eggs, tahini, and vanilla until fully combined. Add in the sugars and whisk until smooth, making sure to break up any clumps of brown sugar.
In a separate bowl, mix the flour, baking powder, and salt, then fold the dry ingredients into the wet mixture until fully combined. Fold in the chocolate chips until mixed well.
Pour batter into the prepared pan and bake for about 40-45 minutes, or until a toothpick or knife comes out clean.
To avoid over-browning or burning, you can top the pan with tin foil after 30-35 minutes or once the top of the bread has browned slightly.