Whisk the flour, sugar, baking powder, and salt together in a large bowl. Using an electric mixer on medium-low speed. Beat the butter into the flour mixture, one piece at a time, about 30 seconds. Continue to beat the mixture until it resembles moist crumbs, 1 to 3 minutes. Beat in the eggs, one at a time, until combined, about 30 seconds. Beat in the milk and vanilla, then increase the mixer speed to medium and beat the batter until smooth, light, and fluffy, 1 to 3 minutes.