Preheat the oven to 350°F. Line two baking sheets with parchment paper and set aside.
To a blender, add 1 cup of the oats, pulse until a coarse flour consistency is reached (you don’t want a super fine flour). Pour the flour into a large bowl and set aside.
To the empty blender, add the banana, peanut butter, egg, melted butter, maple syrup, and vanilla. Pulse just a few seconds until mostly smooth, with a few banana chunks remaining. Pour the mixture into the bowl with the blended oats.
To the same bowl, add the remaining 1 cup of oats, chocolate chips, and salt. Stir to combine. Let the mixture sit for about 5 minutes before scooping to allow it to thicken up a bit (it will still be quite wet).
Scoop the cookie dough onto the prepared baking sheets, using about 2 tablespoons per cookie. Reshape the cookies into circles if needed, and flatten the tops slightly with the back of a spoon to around ¼ and ½ inch thick. Sprinkle with more chocolate chips if desired.
Bake for 11–13 minutes, until the edges are golden and the centers look just set (they should look slightly undercooked in the middle).
Remove from the oven and sprinkle with flaky sea salt if using. Let them cool on the cookie sheets for about 5 minutes before transferring to a cooling rack to finish cooling completely.
