Before anything else, set your oven to 350 degrees Fahrenheit. Then, grease and flour three pieces of 6-inch round cake pans and line them with parchment paper.
After that, whisk off the flour, baking powder, and salt in a medium-sized bowl. Then, set it aside.
Afterward, attach your stand mixer with a paddle attachment. Then, beat the butter until it becomes smooth. After that, add the sugar. Then, beat the mixture for about 2 to 3 minutes on medium-high until it becomes fluffy and light.
Then, lessen the speed and add the egg whites gradually, mixing well after each addition. After that, add the vanilla extract.
Afterward, alternately add the flour mixture and champagne, starting and ending with the flour mixture. Then, three additions of flour and two champagne. Ensure to incorporate well after each addition.
After that, add a bit of Fuschia gel food coloring and mix to combine. But, you should never overmix.
Afterward, spread the batter evenly into the prepared round cake pans and smooth the top using a rubber spatula.
Then, bake it inside the oven for about 35 minutes or until it cooks thoroughly.
Finally, put the cakes on top of a wire rack. Then, let them cool for about 10 minutes.