2 1/2 cups cake flour , plus extra for dusting pans
1 1/4 teaspoons baking powder
1/4 teaspoon baking soda
3/4 teaspoon table salt
1 3/4 cups sugar (12 1/4 ounces)
10 tablespoons (1 1/4 sticks) unsalted butter , melted and cooled slightly
1 cup buttermilk , room temperature
3 tablespoons vegetable oil
2 teaspoons vanilla extract
6 large egg yolks , room temperature
3 large egg whites , room temperature
Add wet ingredients to dry while mixer is running on low. Beat until just combined.
Fold in egg whites with a rubber spatula.