Directions

1. Preheat oven to 350 degrees. Butter two 9-by-2-inch round cake pans; line the bottoms with parchment paper. Butter parchment, and dust with flour, tapping out excess; set aside. Into a medium bowl, sift together flours, baking powder, and salt; set aside.
2. In the bowl of an electric mixer fitted with the paddle attachment, beat the butter and sugar until light and fluffy, 3 to 4 minutes, scraping down the sides of the bowl as needed. Beat in eggs, one at a time, then beat in vanilla. With the mixer on low speed, add the flour mixture in three parts, alternating with the milk and beginning and ending with the flour; beat until combined after each addition.
3. Divide batter between the prepared pans, and smooth with an offset spatula. Bake, rotating the pans halfway through, until cakes are golden brown and a cake tester inserted into the center comes out clean, 30 to 35 minutes. Transfer pans to a wire rack to cool 20 minutes. Invert cakes onto the rack; peel off the parchment. Reinvert cakes and let them cool completely, top sides up.