In a large bowl, whisk flours, brown sugar, baking powder and salt. In another bowl, whisk egg whites, egg, milk and oil until blended. Add to dry ingredients, stirring just until moistened. Fold in apple and walnuts.
Heat a griddle coated with cooking spray on medium heat. Pour batter by 1/4 cupfuls onto griddle. Cook until bubbles on top begin to pop and bottoms are golden brown. Turn; cook until second side is golden brown. Serve with syrup. Freeze option: Freeze cooled pancakes between layers of waxed paper in a resealable freezer container. To use, place pancakes on an ungreased baking sheet, cover with foil and reheat in a preheated 375° oven 6-10 minutes. Or place a stack of three pancakes on a microwave-safe plate and microwave on high for 1-1/4 to 1-1/2 minutes or until heated through.