Preheat oven to 350 degrees.
In a medium mixing bowl whisk together the flour, baking powder, and salt, set it aside.
In a large liquid measuring cup mix together the milk and water, set it aside.
In the bowl of your mixer cream the butter and sugar together about 5-6 minutes until the mixture has lightened.
Mix in the sour cream and almond extract to the butter mixture, using a rubber spatula scrape down the edges of the bowl.
Slowly stir in the egg whites one at a time until each egg is incorporated.
Add in half the flour mixture to the mixing bowl, then half the milk mixture, scrape down the sides of the bowl. Mix in the remainder of the flour mixture then the remainder of the milk mixture.
Scoop the batter into each cupcake wrapper so they are 3/4 full.
Bake for 10 minutes then rotate your pans so the pan that was on the top rack is now on the bottom and vise verse. Continue to bake for an additional 6-10 minutes until the toothpick comes out clean from the center.
Place the cakes on a cooling rack with a sheet pan underneath them until they are cool.