Preheat oven to 350 degrees F. Line 24 standard muffin tins with paper liners.
Have all ingredients measured out and ready to go.
Mix the cake flour, baking powder and salt together in a bowl and set aside.
In bowl of a stand mixer, beat the egg whites until soft peaks form. Gradually beat in 2 tablespoons of the sugar (from the original 1 ¾ cup) and keep beating until whites are almost stiff. If they get too stiff, they're more difficult to fold in, but you want them to have plenty of volume. With a large rubber scraper, remove the whites from the stand mixer bowl and set aside in another bowl.
Add butter to stand mixer bowl and beat until creamy. Gradually add sugar and beat for about 5 minute, scraping sides of bowl often. Beat in salt, vanilla and almond extract (if using) and continue scraping sides.
Beginning and ending with the flour mixture, add the flour and the milk alternately (flour, milk, flour, milk, flour). Scraping and mixing until batter is relatively smooth.
Fold the egg whites into the batter. At this point, you can decide how you want to dress up the cupcake batter. You can add mini chocolate chips, a couple of tablespoons of sprinkles, or divide the batter among little cups and dye it with gel paste.
Divide batter evenly among the cupcake pans and bake on center rack for 22 minutes. Let cool and spread with vanilla icing.
To make the icing, mix the sugar and butter on low speed of an electric mixer. Increase speed to medium and beat for another 3 minutes, scraping sides of bowl often. Add vanilla and a tablespoon of the cream. Continue beating, scraping sides and adding cream until you get the right consistency. Taste and add salt if needed (only if using unsalted butter).
Add vanilla and cream and continue to beat on medium speed for 1 minute more, adding more cream if needed for spreading consistency
Notes
The batter also makes an excellent basic white cake.