Preheat the oven to 350 F. Line two baking sheets with silicone mat or parchment paper and set aside.
Sift the flour, baking soda, kosher salt and ground cinnamon in a medium bowl and set it aside.
In a bowl of a stand mixer with paddle attachment beat the butter, sugars (brown and granulated sugar) and vanilla extract until creamy and smooth.
Scrape the bottom of the bowl and add banana. Mix at a low speed. At this point the batter will look curdled, it is expected!
Add the flour mix and mix on a low speed until everything is combined and no longer has dry streaks of flour.
Fold in the chocolate chips in the batter with hand. The chocolate chip distribution should look almost uniform.
Portion a 1/4 cup size cookie dough and place on the prepared baking sheets, 2 inch apart.
Bake on sheet at time for 15 to 20 minutes, rotating the sheet midway.
Once the baking sheet is out of the oven, immediately bang it against a heat proof hard surface. This will help flatten the puffed cookies.
Let the cookies cool for 5 minutes in the sheets and then transfer to wire rack.
Enjoy warm or store them in an airtight container (once they are completely cooled down) at room temperature for 2 days.