Heat oven to 325 degrees F. Coat two 9-inch round baking pans with nonstick cooking spray. Dust with flour and discard excess. (Alternatively, use a 13 x 9 x 2-inch pan.)
Sift flour, baking powder and salt into a small bowl.
With an electric mixer set on medium, beat butter and sugar until light and fluffy, 2 minutes (this is called creaming). Beat in eggs, one at a time. Beat in vanilla.
On low speed, alternately beat in flour mixture and milk, beginning and ending with flour. Spread batter into prepared pans, dividing equally.
Bake at 325 degrees for 40 to 43 minutes or until a toothpick inserted in center of cakes comes out clean. Cool layers in pans on wire rack for 10 minutes. Run a thin knife around pan edge and turn out cakes to cool completely on racks. Once cooled, spread with Milk Chocolate Frosting. Makes 16 servings.