vanilla-vanilla cupcakes

my december cooking light previewed these great cupcakes and this is by far my favorite combination.

vanilla-vanilla cupcakes
what you need...Cupcakes:
8 ounces cake flour (about 2 cups)
1/2 teaspoon salt
1/2 teaspoon baking soda
1/2 teaspoon baking powder
1/2 cup butter, softened
1 1/4 cups sugar
2 large egg yolks
1 teaspoon vanilla extract
1 cup whole buttermilk
3 large egg whites
1/4 teaspoon cream of tartar

Frosting:
1 cup sugar
1/4 cup water
1/2 vanilla bean
3 large egg whites
1/4 teaspoon cream of tartar
1/8 teaspoon salt
1/4 cup butter, softened

what to do...Preheat oven to 350°. To prepare cake, weigh or lightly spoon flour into dry measuring cups; level with a knife. Combine flour, 1/2 teaspoon salt, baking soda, and baking powder. Place 1/2 cup butter and 1 1/4 cups sugar in a large bowl; beat with a mixer at high speed until well blended. Add egg yolks, 1 at a time, beating well after each addition. Stir in vanilla extract. Reduce mixer speed to low. Add the flour mixture and buttermilk alternately to butter mixture, beginning and ending with flour mixture, and beat just until combined. Using clean, dry beaters, beat 3 egg whites and 1/4 teaspoon cream of tartar at high speed until stiff peaks form. Fold one-third of egg whites into batter. Gently fold in the remaining egg whites. Line 24 muffin cups with cupcake liners; coat with baking spray. Spoon batter into cups. Bake at 350° for 23 minutes or until a wooden pick inserted into centers comes out with moist crumbs clinging. Cool in pans 10 minutes. Remove from pans; cool completely on wire racks.

To prepare frosting, place 1 cup sugar, 1/4 cup water, and vanilla bean in a saucepan; bring to a boil. Without stirring, cook 3 minutes or until a candy thermometer registers 250°; discard vanilla bean. Combine 3 egg whites, 1/4 teaspoon cream of tartar, and 1/8 teaspoon salt in a large bowl; using clean, dry beaters, beat with a mixer at high speed until foamy. Pour hot sugar syrup in a thin stream over egg whites, beating at high speed until stiff peaks form. Reduce mixer speed to low; continue beating until mixture cools (12 minutes). Beat 1/4 cup butter until light and fluffy. Fold in 1 cup egg white mixture. Fold butter mixture into remaining egg white mixture, stirring until smooth. Top cupcakes with frosting.