Preheat oven to 350 degrees. In a large mixing bowl, mix together the oats, bran, almonds, cranberries, baking powder, cinnamon, salt, and orange zest.Put the banana, egg, milk, maple and vanilla into a food processor or blender and blend until smooth. Pour this mixture over the dry ingredients and mix well.Spray an 9 x 9 pan with cooking spray and place a square of parchment in the bottom the pan. Pour in the batter and gently spread evenly, pressing to the corners. Bake for 30 minutes then allow to cool. Cut into equal sized bars. Keep bars in an airtight container or wrap individually.