In a skillet, heat butter over medium-high heat. Add apple; cook and stir 3-4 minutes or until tender. Stir in brown sugar, maple syrup and cinnamon; cook and stir 1 minute longer. Remove from heat; keep warm.
In a large bowl, whisk flour, sugar, baking powder, pie spice and salt. In another bowl, whisk eggs, milk, pumpkin and oil until blended. Add to flour mixture; stir just until moistened. Stir in walnuts.
Lightly grease a griddle; heat over medium heat. Pour batter by scant 1/3 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 apple topping.
To toast nuts, bake in a shallow pan in a 350° oven for 5-10 minutes or cook in a skillet over low heat until lightly browned, stirring occasionally.
Freeze cooled pancakes between layers of waxed paper in a resealable plastic freezer bag. To use, place pancakes on an ungreased baking sheet, cover with foil and reheat in a preheated 375° oven for 5-10 minutes. Meanwhile, prepare apple topping as directed; serve with pancakes.
Nutrition facts per 2 pancakes with 1/4 cup topping: 459 calories, 24g fat (5g saturated fat), 106mg cholesterol, 537mg sodium, 54g carbohydrate (25g sugars, 3g fibre), 11g protein.