To start, preheat your oven to 350 degrees F. Place one rack one-third from the bottom and another two-thirds from the bottom. Line three 9-inch cake pans with parchment paper rounds to prevent sticking, then spray them with Baker's Joy or grease with butter and flour.
In a medium mixing bowl, combine the cake flour, baking soda, salt, and baking powder. Whisk them together until they are well blended. This mixture will provide the foundation for your cake.
In a large bowl, using an electric mixer, cream together the unsalted butter and sugar on medium speed for about 2 minutes until it becomes light and fluffy. This step is crucial as it incorporates air into the batter.
Scrape the sides of the bowl, then add the egg whites and vanilla. Beat on medium speed for another minute until everything is well combined and smooth.
Now it’s time to add the dry ingredients. Start by mixing in one-third of the flour mixture. Beat on medium speed until just incorporated, then add half of the buttermilk and mix until combined.
Continue alternating between adding the dry ingredients and the buttermilk, finishing with the last third of the flour mixture. The batter will be thick and glossy, a sign that it’s ready for the oven.
Divide the batter evenly among the three prepared cake pans. Place two pans on one oven rack and the third on the other, staggering them to ensure even baking.
Bake the cakes for 25 to 35 minutes. You’ll know they’re done when the tops appear flat and golden brown. A toothpick inserted in the center should come out clean.
Let the cakes cool in their pans for about 10 minutes. Then carefully invert them onto wire racks to cool completely. You can wrap them in plastic wrap and freeze for up to 3 weeks if you're making them ahead of time.
For the frosting, in a medium bowl, beat the softened unsalted butter with the cherry juice until it’s smooth and creamy. Gradually add in the powdered sugar, mixing until it's fluffy. Stir in the chopped maraschino cherries gently.
Once the cakes have cooled, spread a layer of frosting between the layers, on top, and around the sides of the cake. Make sure it’s nice and thick for that perfect finish!
