1. Prick sweet potatoes with a fork in several places. Place in baking dish and bake at 425ºF until tender all the way to the center, about 1 hour.
2. When cool enough to handle, peel off and discard skin. Transfer the sweet potatoes to a medium bowl and mash thoroughly with a potato masher. Add coconut milk, ginger and salt; stir well. Reheat in the microwave for 1-2 minutes or in the oven for 8-10 minutes. Serve warm.