Preheat the oven to 350° F. Line a cookie sheet with parchment paper or a silicone liner and set aside.
In the bowl of a stand mixer, cream together the salted butter, granulated sugar, brown sugar and overripe banana for 1 minute, or until light in color and fluffy in texture.
Scrape the sides of the bowl and add in the vanilla. Mix until well combined.
Add the flour, blended rolled oats (into a rough oat flour), baking soda, cinnamon, and salt to the mixer. Mix until a soft dough or thick batter forms.
Scoop your cookies out using a #40 scoop, or portion the cookie dough into 1 1/2 tbsp portions.
Roll each portion into the cinnamon and sugar mixture and then arrange on a cookie sheet.
Bake at 350° F for 9-11 minutes or until the cookies puff up slightly, and the centers of the cookie no longer look wet.
Allow the cookies to cool on the pan for 15 minutes.
Enjoy!