1Heat oven to 350° F (325° F for dark or nonstick pans). Line 24 regular-size muffin cups with gold metallic paper baking cups. Make and bake cupcakes as directed on box. Cool cupcakes completely before frosting.
2Transfer frosting to large decorating bag fitted with a star tip. Pipe frosting onto cooled cupcakes. Let cupcakes stand uncovered until frosting is set, about 2 hours. Gently touch-test frosting with fingertip-the outside should be dry to the touch. If frosting is still wet and smears, allow additional drying time.
3When frosting is set, load small soft-bristle dry artist's brush with gold luster dust. Gently brush over frosting portion of a cupcake until a gold sheen is achieved. Repeat with remaining cupcakes. A second coat of luster dust can be applied for intensified golden color.
4Store cupcakes loosely covered with plastic wrap or in air-tight plastic cupcake-keeper.