Preheat oven to 400 degrees F. Prick sweet potatoes with a fork and place on a rimmed baking sheet lined with parchment paper. Bake 1 hour or until verty tender. Remove from oven and let cool slightly. Reduce oven temperature to 350 degrees.
Meanwhile, to make the crust, stir together ground gingersnaps, coconut and butter in a medium bowl until moistened and well combined. Press mixture into and up the sides of a 9-inch pie dish. Bake about 15 minutes or until golden. Let cool slightly.
To finish the filling, peel roasted potatoes and transfer flesh to the bowl of a food processor. Discard skins. Process until potatoes are pureed. Add coconut milk, brown sugar, eggs, cinnamon, nutmeg and salt and process until evenly combined.
Pour sweet potato filling into crust and bake about 50 minutes or until just set in the center of the pie. Let cool to room temperature on a wire rack. Serve or chill in refrigerator until ready to serve.