Bake the sweet potatoes in a pre heated oven at 350 degree for about an hour and a half, or till very soft and caramelized. The potatoes may turn dark and the sugars may blacken around the potato. Let them cool enough to touch. Then remove the flesh of the potato and place in a bowl. Add the ginger, orange juice and ½ t salt. Mix with a hand mixer till smooth. Place in a serving bowl and top with nuts.