Working Blue Cupcakes: Ginger Cupcakes with Peach Filling and Blueberry Frosting

Name: Working Blue Cupcakes: Ginger Cupcakes with Peach Filling and Blueberry Frosting
Ingredients: 1 pound 10 ounces unbleached flour; 2 tablespoons baking powder; 1 teaspoon salt; 1 pounds 4 ounces sugar; 9 ounces, scant, non-hydrogenated vegan margarine (recommended: Earth Balance); 1/2 cup water; 1 tablespoon egg replacer (recommended: Ener-G); 2 tablespoons ginger juice, commercial or fresh; 1 1/2 cups plus 2 tablespoons soy milk; 1 tablespoon vanilla extract; 1/2 cup minced ginger, packed (about 6 ounces whole, unpeeled ginger root); 2 cups prepared peach puree, store-bought; 3 tablespoons sugar; 1 tablespoon water or brandy; 1 tablespoon cornstarch; 12 ounces non-hydrogenated vegetable shortening (recommended: Earth Balance); 4 ounces non-hydrogenated vegan margarine (recommended: Earth Balance); 6 ounces blueberry puree, store-bought; 1 teaspoon vanilla extract; 1 pound 13 ounces powdered sugar; 2 tablespoons blueberry juice concentrate; Fresh blueberries, for garnish, optional