Preheat oven to 350°F. Line 24 muffin tins with paper liners and set aside.
In the bowl of your mixer, combine cake mix, champagne, vegetable oil, and egg whites. Beat on low for 30 seconds, then increase speed to medium and beat for two minutes.
Fill liners 2/3 full and bake for 10 -15 minutes or until tops spring back when lightly touched in the center. Remove from oven and let cool completely on wire racks before topping with glaze.
Whisk together champagne and powdered sugar until smooth.
Dip the tops of the cupcakes in the glaze, letting the excess drip off before placing back on your wire rack until the glaze is firm.