For the Fluffy White Cake:
5 large egg whites, at room temperature
1 cup whole milk, at room temperature
2-1/4 teaspoons pure vanilla extract
3 cups cake flour, sifted
1-3/4 cups sugar
1 tablespoon + 1 teaspoon baking powder
3/4 teaspoon salt
12 tablespoons unsalted butter, at room temperature and cut into cubes
1. Preheat oven to 350°F. Grease, or use cupcake liners.
2. In a medium bowl, combine and stir the egg whites, 1/4 cup of milk, and the vanilla. Set aside.
3. In the bowl of an electric mixer fitted with the paddle attachment, combine the dry ingredients together on low speed for 30 seconds.
4. Add the butter and remaining milk, and mix on low speed until just moistened. Increase to medium speed and mix for 1-1/2 minutes. Scrape the sides of the bowl and begin to add the egg mixture in 3 separate batches; beat on medium speed for 20 seconds after each addition.
5. Fill cupcake liners 3/4 of the way for a nice top.
6. Bake 23 minutes or until a center comes out clean when inserted into the center. Be so careful to not over-bake. Check cupcakes at 15 minutes, but not before. You want just a slight golden brown. Let cool on racks for 15 minutes.
Refrigerator for up to 5 days, or frozen for up to 2 months. Best eaten the same day as baked.
For the Whipped Vanilla Bean Frosting:
2½ sticks unsalted butter, softened
1 vanilla bean, halved lengthwise
2½ cups confectioners’ sugar (10 ounces)
1 teaspoon vanilla extract
2 Tablespoons heavy cream
For the Fluffy White Cake
1. In a standing mixer fitted with the whisk attachment, beat the butter at medium-high speed until smooth, about 20 seconds. Using a paring knife, scrape seeds from vanilla bean into butter and beat mixture at medium-high speed to combine, about 15 seconds.
2. Add confectioners’ sugar and salt; beat at medium-low speed until most of the sugar is moistened, about 1 minute. Scrape down the bowl and beat at medium speed until mixture is fully incorporated, about 30 seconds; scrape bowl, add vanilla and heavy cream, and beat at medium speed until incorporated, about 20 seconds, then increase speed to medium-high and beat until light and fluffy, about 4 minutes, scraping down bowl once or twice.