2Mix brown sugar, shortening, egg, and lemon zest together in a bowl until creamy. Stir in flour, baking soda, cream of tartar, ginger, and salt until dough comes together.
3Pour white sugar onto a plate. Roll dough into 1-inch balls; dip 1 side in white sugar. Arrange balls, sugared-side up, on 2 baking sheets.
4Bake in the preheated oven until edges are pale golden and tops look dry, 10 to 12 minutes.