Allow butter and eggs to stand at room temperature for 30 minutes. Meanwhile, line cupcake cups with paper liners. In a medium bowl combine flour, baking powder, and salt; set aside.
In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Gradually add sugar, about 1/4 cup at time, beating on medium speed until well combined and scraping sides of bowl. Beat on medium speed for 2 minutes more. Add eggs, one at a time, beating after each addition (about 1 minute total). Beat in vanilla. Add flour mixture and milk alternately to beaten mixture, beating on low speed after each addition just until combined. Fill each cup half full.
Bake in a 375 degree F oven for 18 to 20 minutes or until a wooden toothpick inserted in center of a cupcake comes out clean. Cool on a wire rack. Makes about 30 cupcakes.