2 cups all-purpose flour
2 teaspoons baking powder
1/4 teaspoon salt
3/4 cup milk
1 1/2 teaspoons vanilla extract
1 1/4 cups sugar
3/4 cup margarine or butter (1 1/2 sticks), softened
3 large eggs
Preheat oven to 350 degrees F. Grease three 8-inch round or two 9-inch round cake pans, or 13" by 9" metal baking pan. Line bottom(s) with waxed paper; grease paper. Dust pan(s) with flour. Or, line twenty-four 2 1/2-inch muffin-pan cups with fluted paper liners.
On waxed paper, combine flour, baking powder, and salt. In 1-cup glass measuring cup, mix milk with vanilla.
In large bowl, with mixer at low speed, beat sugar and margarine or butter until blended. Increase speed to high; beat until creamy, about 5 minutes. Reduce speed to medium-low; add eggs, 1 at a time, beating well after each addition.
With mixer at low speed, alternately add flour mixture and milk mixture, beginning and ending with flour mixture; beat just until batter is smooth, occasionally scraping bowl with rubber spatula (batter may look curdled).
Pour batter into pan(s). Bake at 40 to 45 minutes for 13" by 9" cake or 23 to 25 minutes for 8- and 9-inch cake layers, until toothpick inserted in center of each cake comes out clean. Or, pour batter into muffin-pan cups. Bake 20 to 25 minutes. Cool cake(s) in pan(s) on wire rack(s) 10 minutes. Run small knife around sides of pan(s) onto wire rack(s) to cool completely; discard waxed paper. Or, remove cupcakes from pans and cool completely.
