Fluffy Yellow Layer Cake

Ingredients

• 2 ½ cups cake flour
• 1 ¼ teaspoons baking powder
• ¼ teaspoon baking soda
• ¾ teaspoon table salt
• 1 ¾ cups sugar
• 10 tablespoons unsalted butter, melted and cooled slightly
• 1 cup buttermilk, room temperature
• 3 tablespoons vegetable oil
• 2 teaspoons vanilla extract
• 6 large egg yolks plus 3 large egg whites, room temperature

Directions

1. Adjust oven rack to middle position and heat oven to 350 degrees. Grease 2 9-inch wide by 2-inch high round cake pans and line bottoms with parchment paper. Grease paper rounds, dust pans with flour, and knock out excess. Whisk flour, baking powder, baking soda, salt, and 1 ½ cups sugar together in a large bowl. In a 4-cup liquid measuring cup or medium bowl, whisk together melted butter, buttermilk, oil, vanilla, and yolks.
2. In the clean bowl of a stand mixer fitted with the whisk attachment, beat egg whites at medium-high speed until foamy, about 30 seconds. With the machine running, add the remaining ¼ cup sugar; continue to beat until stiff peaks just form, 30 to 60 seconds. Transfer to a bowl and set aside.
3. Add the flour mixture to the now-empty mixer bowl fitted with the whisk attachment. With the mixer running at low speed, gradually pour in the butter mixture and mix until almost incorporated (a few streaks of dry flour will remain), about 15 seconds. Stop mixer and scrape whisk and sides of bowl. Return mixer to medium-low speed and beat until smooth and fully incorporated, 10 to 15 seconds.
4. Using a rubber spatula, stir 1/3 of the whites into the batter to lighten, then add the remaining whites and gently fold into the batter until no white streaks remain. Divide batter evenly between prepared cake pans. Lightly tap pans against counter 2-3 times to dislodge large air bubbles.
5. Bake until cake layers begin to pull away from sides of pans and a toothpick inserted into the center comes out clean, 20-22 minutes. Cool cakes in pans on a wire rack for 10 minutes. Loosen cake from sides of pans with a small knife, then invert onto a greased wire rack and peel off parchment. Invert cakes again and cool completely on rack, about 1 ½ hours.