½cup(113g)unsalted butter, (1 stick) room temperature
1cup(200g)granulated sugar
2tspclear vanilla , (for whiter cupcakes; regular vanilla is also fine)
3large egg whites, room temperature (no yolks)
½cup(118ml)milk, room temperature
Instructions
Preheat the oven to 350℉ (or 375℉ for high altitude) and line cupcake pan(s) with paper liners. Set aside.
Sift the dry ingredients (flour, cornstarch, baking powder, and salt) together with a fine mesh sieve. Set aside.
In the bowl of a stand mixer with the paddle attachment, cream the butter and sugar together on high speed for 2 minutes. (Set a timer.)
Add the clear vanilla and egg whites. Beat on medium speed until combined. Add 1/3 of the flour mixture. Mix on low speed until just combined. Add 1/2 of the milk. Mix on low speed until just combined.
Repeat, alternately mixing in another 1/3 of the flour mixture, the remaining milk, and ending with the final 1/3 of the flour mixture. Do not over-mix. The batter should be thick and smooth looking.
Use a rounded #24 scoop to fill cupcake liners 2/3 full.
Bake at 350℉ (or 375℉ for high altitude) for 16-18 minutes or until the cake springs back when touched in the center, or a toothpick inserted comes out with a few moist crumbs. NOTE: These cupcakes are better slightly less done. Do not over-bake!
Allow cupcakes to cool in pan for 5 minutes before transferring to a wire rack to cool completely. Top with desired frosting once cool. I used my vanilla buttercream frosting recipe.
Notes
Cupcakes last 2-3 days when stored in an airtight container at room temperature.