1Preheat the oven to 375 degrees F (190 degrees C).
2Melt shortening in a saucepan large enough for mixing the dough. Mix in sugar and molasses. Combine the flour, salt, baking soda, nutmeg, and ginger; gradually stir into the pan, using your hands to work in the last bit. Dough should be stiff.
3On a floured surface, roll out dough to 1/4 inch thickness, and cut out as desired. Make sure the gingerbread is of uniform thickness, or the edges may burn before the center is done. Place pieces onto cookie sheets.
4Bake for 13 to 15 minutes in the preheated oven. Let cool for several minutes on the cookie sheet, then remove to racks to finish cooling.
5When the gingerbread has cooled completely, make the frosting cement. In a medium bowl, mix together confectioners' sugar and cream of tartar. Add egg whites and vanilla. Beat on high speed until frosting holds its shape. If necessary, add more confectioners' sugar to thicken the icing. Cover frosting with a damp cloth to prevent drying.