Yes, you can sprinkle luster dust on a cake as it is specifically designed for this purpose. Luster dust is a type of edible powder that adds a shimmery or metallic effect when applied to cakes or other confections. It is usually available in an array of colors and shades, including gold and silver tones. Sprinkling luster dust over a cake can give it an elegant finishing touch, making it visually appealing and adding a touch of glamour.