Preheat your oven to 375º and line two sheet pans with parchment paper.

In a medium bowl, stir together the flour, baking soda, and salt. Set aside.

In the bowl of a stand mixer, add the brown sugar and melted butter. Mix on medium low speed until well combined, about 45 seconds.

Reduce the speed to low and add in the mashed banana and vanilla. Mix until combined.

Keep the mixer on low speed and add in the flour mixture. Stop mixing once the ingredients are almost fully combined. Leave some streaks of flour remaining.

Add in the chocolate chips and scrape down the sides of the bowl.

Finish mixing the cookie dough on low speed until the chocolate chips are evenly distributed and no more streaks of flour are showing.

Remove the bowl from the mixer. Using a rubber spatula, scrape down the sides and bottom of the bowl to ensure all the ingredients are fully combined. 

Scoop the cookie dough about 2 tablespoons in size (a #30 cookie scoop) onto your prepared sheet pans. Space the cookies about 2" apart and let them sit at room temperature for 10-15 minutes to let the flour hydrate.

After the dough has rested, bake the banana bread cookies at 375º until the edges are golden brown and the centers are puffed, 11-12 minutes for gooey cookies and 13-14 minutes for cakier cookies.

Let the cookies sit on the cookie sheet for a few minutes to cool down before transferring to a wire rack or serving plate.