Preheat the oven to 350 degrees F. Line 2 baking sheets with parchment paper or silicone baking mats.
Place the bananas in the bowl of a stand mixer fitted with the paddle attachment. Beat until the bananas are mashed. Stop the machine and add in the oats, chopped dates, oil, cinnamon, chocolate chips and salt. Mix on low to medium speed until the bananas are in very small pieces, the batter is moist and the ingredients are well combined, about 30 seconds.
Using a mini ice cream scoop or tablespoon, scoop the batter into thirty 1-inch balls, spacing them evenly over the prepared baking sheets. Gently pat each ball to flatten into a round.
Bake until the cookies just start to turn golden brown and dried on top, about 25 minutes. Transfer to a wire rack to cool.
Serve or freeze in a resealable plastic bag for up to 3 months.
To make bars instead of cookies, bake the batter in a greased 7-by-11-inch baking dish for 35 to 40 minutes then let cool. Cut into bars or squares.