Combine oats, oat flour, cinnamon, baking soda and salt in a large bowl. Mash bananas in a medium bowl until creamy. Add eggs, coconut oil (or butter) and vanilla; whisk until well combined. Add the dry ingredients and dates (or raisins) and coconut to the banana mixture; stir until combined. Roll tablespoons of dough into balls and place on the prepared baking sheet, making 15 cookies per batch. Press with a fork to flatten slightly.