Preheat oven to 350 and line a baking sheet with parchment paper. In a large bowl, combine flour, oats, baking powder and baking soda. In a small bowl combine banana, maple syrup and milk. Add wet ingredients to dry ingredients and stir well. Spoon into 6-8 cookies and place on baking sheet, bake for 10 minutes or until done. For glaze, mix ingredients in a bowl and spread on cooled cookies.