Preheat your oven to 350 degrees F.

Line a 9x5 loaf pan with parchment paper and spray it lightly with nonstick baking spray, set aside.

In a large bowl, whisk together the mashed banana, melted butter, brown sugar, egg, and vanilla. 

Add the flour, baking soda, and kosher salt. Mix just until no large lumps remain. 

Add the chocolate chips and fold them in gently. 

Transfer the batter to the prepared pan and top with additional chocolate chips, if desired. 

Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean. 

Remove the bread from the oven and allow it to sit on a wire rack for 10 minutes.

Then, remove the bread from the pan and allow it to cool to room temperature before slicing. 

Store any leftover banana bread in an airtight container in the fridge for up to three days.