Preheat the oven to 375°. Line two cupcake pans with paper liners and set aside. In a medium bowl, sift together the flour, baking powder, and salt.
In a large bowl using an electric mixer, beat the butter and the sugar until light and fluffy, about three minutes. Beat in the eggs one at a time, then beat in the vanilla extract.
Add one-third of the flour mixture and beat to combine. Add half of the milk and beat to combine. Add another third of the flour, then the remaining milk, then the rest of the flour, beating to combine after each addition.
Divide the batter between the liners, filling each about 2/3 of the way full. Bake for 18 to 20 minutes, or until the cupcakes are golden-brown and spring back when pressed lightly. Transfer to a wire rack to cool completely, then frost with Simple Buttercream Frosting.