White Cake Layers

3 1/4 cups (11.5 oz/325 g) sifted cake flour
1 tablespoon baking powder
3/4 teaspoon salt
1 cup (2 sticks/8 oz/227 g) unsalted butter, softened
1 1/2 cups (10.6 oz/300 g) granulated sugar
6 large egg whites
1 teaspoon finely grated lemon zest (optional)
2 teaspoons vanilla extract
1 1/3 cups (320 ml) whole milk

Position a rack in the center of the oven and heat the oven to 350° F. Grease the bottom and sides of two 9-inch round cake pans.  Dust the pans with flour.

Sift together the cake flour, baking powder, and salt into a medium bowl.  Whisk to combine, and set aside.

In the bowl of a stand mixer, using the paddle attachment, beat the butter at medium-high speed until creamy, about 30 seconds.  Gradually add the sugar and beat at high speed until light, about 2 minutes.  Reduce the speed to low and add egg whites, one at a time, beating well after each addition and scraping down the sides of the bowl occasionally.  Beat in the lemon zest and vanilla extract.  (Use a spatter shield if you have one, or drape a kitchen towel over the mixer.)  Add the flour mixture at low speed in three additions, alternating it with the milk in two additions and mixing just until the flour is incorporated.  Scrape the batter into the prepared pans, dividing it evenly, and smooth the tops.

Bake the cake 25 to 30 minutes, until lightly browned around the edges.  Cool the cakes in the pans on wire racks for 15 minutes.  Invert the layers onto the racks and cool, upside-down, completely.

Store at room temperature, covered in foil, for up to 5 days.

Makes two 9-inch cake layers.

From The Cake Book by Tish Boyle