Step 1

Preheat oven to 350°F (177°C). Line a 12-count muffin pan with cupcake liners. This recipe only makes 16-18 cupcakes, so you’ll have 4-6 cupcakes to bake in a 2nd batch.

Step 2

With a handheld or stand mixer fitted with a whisk attachment, beat 2 egg whites on high speed in a medium bowl until soft peaks form, about 2-3 minutes. You want them very fluffy; no liquid at the bottom of the bowl (which makes for too much liquid in the batter). See photo at the bottom of this post for a visual. Set aside.

Step 3

Whisk the flour, baking powder, and salt together in a medium bowl. Set aside.

Step 4

Using a handheld or stand mixer fitted with a paddle attachment, beat the butter on high speed until smooth and creamy, about 1 minute. Add the sugar and beat on high speed for 2-3 minutes until creamed together fairly well. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed. Add two egg yolks and the vanilla. Beat on medium-high speed until combined. Scrape down the sides and up the bottom of the bowl with a rubber spatula as needed. With the mixer on low speed, add the dry ingredients in three additions alternating with the whole milk, beginning and ending with the dry ingredients, and mixing each addition just until incorporated. Do not over-mix. Fold whipped egg whites into cupcake batter. The batter will be smooth, velvety, and slightly thick.

Step 5

Spoon batter into cupcake liners filling halfway full. Bake for 18-21 minutes or until the tops of the cupcakes spring back when gently touched and a toothpick inserted in the center comes out clean. Mine usually take 21 minutes. Don’t over-bake. Allow to cool in the pan for 5 minutes, then transfer to a rack to cool completely.

Step 6

Prepare chocolate buttercream. Pipe or spread the frosting onto cooled cupcakes. Decorate with sprinkles.