01 - Preheat your oven to 350°F (175°C). Line a 12-cup muffin tin with paper cupcake liners.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, and salt until thoroughly combined. Set aside.
03 - In a large mixing bowl, using an electric mixer, cream together the softened unsalted butter and granulated sugar until the mixture is light and fluffy, which typically takes about 2 to 3 minutes.
04 - Add the eggs one at a time to the butter mixture, beating well after each addition to ensure full incorporation. Stir in the vanilla extract until just combined.
05 - With the mixer set to low speed, gradually alternate adding the dry flour mixture and the sparkling pink grape juice to the butter mixture. Begin and end with the flour mixture, mixing until just combined and being careful not to overmix. If desired, incorporate pink food coloring at this stage.
06 - Evenly distribute the prepared cupcake batter among the lined muffin cups, filling each approximately two-thirds full.
07 - Bake for 18 to 20 minutes, or until a wooden skewer inserted into the center of a cupcake comes out clean. Allow the cupcakes to cool in the muffin tin for 5 minutes before carefully transferring them to a wire rack to cool completely.
08 - For the frosting, beat the softened butter in a clean bowl until creamy. Gradually add the sifted powdered sugar, mixing thoroughly. Incorporate the sparkling pink grape juice, vanilla extract, a pinch of salt, and food coloring (if using). Continue beating until the frosting achieves a light and fluffy consistency.
09 - Once the cupcakes are entirely cool, apply the pink champagne frosting using a piping bag or an offset spatula. For an enhanced presentation, garnish with edible glitter or sprinkles, if desired.