Yield: One 2-layer, 8-inch round cake
5 large egg whites (5 ounces/150 grams) at room temperature
3/4 cup whole milk (180 mL/6 liquid ounces), at room temperature
2 1/4 teaspoons pure vanilla extract (9 grams) — I use Nielsen-Massey Vanillas 8-oz. Madagascar Bourbon Vanilla Extract
2 3/4 cups cake flour, sifted (11 ounces/315 grams)
1 3/4 cups sugar (12 ounces/350 grams)
1 tablespoon + 1 teaspoon baking powder (19.5 grams)
3/4 teaspoon salt (5 grams)
12 tablespoons unsalted butter (6 ounces/170 grams), at room temperature and cut into cubes
1. Preheat oven to 350°F (180°C). Grease, line with parchment, and flour two round 8-inch pans.
2. In a medium bowl or measuring cup, 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 (I use the “stir” setting on my mixer) for 30 seconds.
4. Add the butter and remaining 1/2 cup of milk, and mix on low speed until just moistened. Increase to medium speed and mix for 1 1/2 minutes.
5. 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.
6. Divide the batter in two, spreading it evenly with a small offset palette knife. If you have a kitchen scale, weigh to ensure 2 even layers.
7. Bake 25-35 minutes or until a cake tester comes clean when inserted into the center. Be so careful to not overbake. Check cake at 20 minutes, but not before, and once you feel it’s almost ready, set the timer for 2 minute intervals. Let cool on racks for 10 minutes before loosening the sides with a small metal spatula, and invert onto greased wire racks. Gently turn cakes back up, so the tops are up and cool completely.
8. Wrap tightly and store at room temperature for up to 2 days, refrigerator for up to 5 days, or frozen for up to 2 months. Best eaten the same day as baked.