In a food processor, combine the flour, salt and ginger; cover and pulse to blend. Add butter and shortening; cover and pulse until mixture resembles coarse crumbs.
While processing, gradually add water just until moist crumbs form. Shape into a disk; wrap in plastic wrap and refrigerate for 30 minutes or until easy to handle.
Preheat oven to 425°. Roll out pastry to fit a 9-in. deep-dish pie plate. Transfer pastry to pie plate. Trim pastry to 1/2 in. beyond edge of plate; flute edges or decorate with pastry cutouts as desired. Line unpricked pastry with a double thickness of heavy-duty foil. Fill with dried beans, uncooked rice or pie weights.
Bake 8 minutes. Remove foil and weights; bake 5 minutes longer. Cool on a wire rack. Reduce oven setting to 325°.
For filling, in a small saucepan, combine the coconut milk, brown sugar and cream cheese. Cook and stir until smooth. Transfer to a large bowl; cool 5 minutes. Whisk in the sweet potatoes, eggs, lemon juice, vanilla, salt and cinnamon. Pour into crust.
Bake 50-60 minutes or until a knife inserted near the center comes out clean. Cover edges with foil during the last 15 minutes to prevent overbrowning if necessary.
For meringue, in a large bowl, beat egg whites and cream of tartar on medium speed until soft peaks form. Gradually beat in sugar, 1 tablespoon at a time, on high until stiff glossy peaks form and sugar is dissolved.
Place marshmallow creme in a separate large bowl; fold in a third of the egg white mixture, then fold in the remaining mixture. Spread evenly over hot filling, sealing edges to crust. Sprinkle with marshmallows and coconut.
Bake 12-15 minutes longer or until top is golden brown. Cool on a wire rack for 1 hour. Refrigerate for at least 3 hours before serving. Store leftovers in the refrigerator. Yield: 8 servings.