Preheat oven to 350°F. Prepare the muffin tins by brushing the sides lightly with melted butter and dusting with flour. You can also use a butter/flour baking spray.
Sift together the flour, baking powder and salt; set aside. In the bowl of an electric stand mixer fitted with the paddle attachment, cream the butter at medium speed until smooth. Slowly add the sugar and continue to mix at medium speed until well combined. Add eggs, one at a time, beating well after each addition and scraping down the sides and bottom of the mixer and the paddle once or twice. Add the vanilla and mix until combined.
Continue to beat on medium-low speed; alternate adding the flour mixture and the milk, beginning and ending with the flour. Scoop the batter into tins until each is just over 3/4 full. Bake in oven until golden and a toothpick inserted in the center comes out clean, about 25 minutes, rotating tins after about 15 minutes.
Homemade Cupcake Fillings and Toppings