Preheat the oven to 350°F. Place a rack in the center of the oven and line a large baking sheet with parchment paper or a silicone baking mat.
Peel the bananas and place them in a large mixing bowl. Mash with a fork until mostly smooth. Small lumps are fine.
Add the nut butter, maple syrup or honey, and vanilla. Stir until the mixture looks smooth and evenly blended.
In a separate bowl, combine the rolled oats, oat flour, chia seeds, ground flaxseed, cinnamon, baking powder, and salt.
Add the dry ingredients to the banana mixture. Fold until no loose flour remains. Avoid heavy stirring.
Fold in the pumpkin seeds, dried fruit, and optional chocolate chips until evenly spread through the dough.
Leave the dough at room temperature for 10 minutes. This gives the oats and seeds time to absorb moisture.
Scoop the dough into 12 equal portions, using about 2 tablespoons for each cookie. Arrange them about 2 inches apart on the prepared baking sheet.
Use the damp back of a spoon to flatten each portion into a round about 1/2 inch thick. The cookies will not spread much while baking.
Bake for 13–16 minutes, until the tops look dry and the edges are lightly golden. The centers should still feel soft.
Let the cookies cool on the baking sheet for 10 minutes. Transfer them to a wire rack or plate and cool for another 10 minutes before serving.
