Preheat the oven to 350 degrees F. Line a 12-cup muffin pan with paper liners. Whisk the flour, baking powder and salt in a bowl. Beat the butter and sugar in a stand mixer fitted with the paddle attachment on medium-high speed until fluffy, about 4 minutes. Beat in the eggs, one at a time, scraping down the bowl as needed. Beat in the vanilla. Reduce the mixer speed to medium low; beat in half of the flour mixture, then all of the milk, then the remaining flour mixture until just combined.
Divide the batter among the muffin cups, filling each three-quarters full. Bake until a toothpick inserted into the center of a cupcake comes out clean, 18 to 20 minutes, rotating the pan halfway through. Transfer the pan to a rack and let cool 5 minutes, then remove the cupcakes to the rack to cool completely. Top with Frosting.
Photograph by Levi Brown
Whisk the egg whites, sugar and salt in a heatproof bowl set over a saucepan of simmering water (do not let the bowl touch the water) until the mixture is warm and the sugar dissolves. Remove the bowl from the pan; let cool slightly.
Beat the egg white mixture in a stand mixer fitted with the whisk attachment (or with a hand mixer) on medium-high speed until stiff peaks form, 12 to 15 minutes. Beat in the butter a few pieces at a time, then continue beating until smooth. (Don't worry if the mixture looks separated at first-it will come together as you keep beating.)
Make sure that your butter is nice and soft (with no chill) or the buttercream may curdled when mixing.
Courtesy of Food Network Magazine