01 - Preheat your oven to 350°F. Line a 12-cup muffin tin with cupcake liners.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.
03 - In a large mixing bowl, beat the softened unsalted butter and granulated sugar together until the mixture is light and fluffy, approximately 2 to 3 minutes.
04 - Add the large eggs one at a time, ensuring each is thoroughly incorporated before adding the next. Stir in the vanilla extract.
05 - With the mixer on low speed, alternately add the prepared flour mixture and the sparkling pink grape juice to the butter mixture. Begin and end with the flour mixture, mixing until just combined. If desired, incorporate the pink food coloring at this stage.
06 - Evenly divide the cupcake batter among the prepared cupcake liners, filling each approximately two-thirds full.
07 - Bake for 18 to 20 minutes, or until a toothpick inserted into the center of a cupcake comes out clean. Allow the cupcakes to cool in the muffin tin for 5 minutes before transferring them to a wire rack to cool completely.
08 - For the frosting, beat the softened unsalted butter until creamy. Gradually add the sifted powdered sugar, mixing thoroughly after each addition. Incorporate the sparkling pink grape juice, vanilla extract, a pinch of salt, and pink food coloring (if using). Continue beating until the frosting is light and fluffy.
09 - Once the cupcakes are completely cool, frost them generously with the pink champagne frosting using a piping bag or an offset spatula. Garnish with edible glitter or sprinkles as desired.