Preheat oven to 350 degrees. Line a sheet pan with parchment paper, silicone baking mat, or lightly grease with oil.
Mash bananas in a large bowl. Stir in oil, maple syrup, egg, vanilla, cinnamon, baking powder, and salt.
Mix in oats and flour until just combined. Stir in about 3/4 of the chocolate chips, reserving some to place on the top.
Scoop about 2 tablespoons of batter at a time onto the prepared pan. Top each cookie with a few chocolate chips. Bake until set and lightly golden brown around the edges, 10 to 12 minutes. Cool for 5 minutes then transfer cookies to a cooling rack. Store cookies in an airtight container at room temp for 2 days, in the fridge for 5 days, and in the freezer for 2 months.