Preheat the oven to 350°F (175°C) and line an 8-inch square baking pan with parchment paper, leaving some overhang for easy removal.
Mash the ripe bananas in a large mixing bowl until smooth; you should have about 1½ cups mashed banana.
Add the creamy almond butter, maple syrup, and vanilla extract to the mashed bananas and stir until the wet ingredients are well combined.
Add the quick oats, cocoa powder, ground cinnamon, and sea salt to the bowl and mix until a thick, even batter forms.
Fold in the chocolate chips if using, reserving a few to sprinkle on top if desired.
Transfer the batter to the prepared pan and spread into an even layer with a spatula; sprinkle reserved chocolate chips on top if using.
Bake on the center rack for 12–16 minutes, or until the edges are set and the center is firm (about 15 minutes is typical).
Allow the bars to cool to room temperature in the pan before using the parchment overhang to lift them out and slice into 9 bars.