Preheat the oven to 350°F and place a rack in the center position.
Line a 9×9-inch baking pan with parchment paper, leaving an overhang on two sides for easy removal.
Place 1 cup mashed banana in a large mixing bowl.
Add 2 tablespoons honey, 3 tablespoons canola oil, 5 tablespoons water, and 1 teaspoon vanilla extract to the bowl and stir until the wet ingredients are combined.
Add 2 cups rolled oats, a pinch of cinnamon, and a pinch of salt to the bowl. Stir until the oats are evenly moistened and the mixture is uniform.
Transfer the mixture to the prepared 9×9-inch pan and use a spatula to spread and press it into an even layer.
Sprinkle a handful of chocolate chips evenly over the top and gently press them into the surface.
Bake for 25 minutes. After 25 minutes, turn off the oven and leave the pan inside with the oven door closed for an additional 5 minutes.
Remove the pan from the oven and place it on a wire rack to cool until firm and cool to the touch.
Use the parchment overhang to lift the baked oatmeal from the pan, place on a cutting board, and slice into bars.