Cut potatoes lengthwise into 1/2-inch thick slices; cut slices into 1/2-inch thick sticks the length of the potatoes. Arrange potatoes in a single layer on 2 ungreased 12x15-inchrimmed baking pans. Spray with Pam. Bake, uncovered, in a 400 degree oven, turning over with a spatula as needed, until evenly browned and crisp, about 1 hour. Sprinkle lightly with salt and pepper. Serve hot.