Heat oven to 400. Spray 12 lg muffin cups w/ cooking spray. In lg bowl, combine flours, baking powder, salt and cinnamon. Make a well in center of bowl. In a medium bowl, whisk together the milk, pumpkin, butter and egg. Add pumpkin mix to well in lg bowl. Add chocolate chips to bowl. Stir until just moistened. Spoon mix into each muffin cup, 3/4 full. Sprinkle nuts evenly over each muffin cup. Bake 18-20 min, or until a toothpick inserted in center comes out clean.