Instructions

1. Preheat oven to 350F.
2. Line muffin tin with 12 cupcake liners. Set aside.
3. In medium bowl, mix flour, baking powder, baking soda and salt. Set aside.
4. In large bowl, melt butter in microwave. 
5. Whisk sugar into butter. (Mixture will be gritty.)
6. Whisk in egg whites, yogurt, milk and vanilla extract until combined. 
7. Split 1 vanilla bean down middle lengthwise. Scrape seeds from half into wet ingredients. Reserve other half for frosting.
8. Slowly mix dry ingredients into wet ingredients until no lumps remain. Batter will be thick.
9. Divide batter among 12 cupcake liners.
10. Bake for 20 minutes or until toothpick inserted in center of cupcake comes out clean.
11. Set cupcakes on wire rack to cool completely before frosting.
12. Beat softened butter on medium speed with electric or stand mixer fitted with paddle attachment for about 3 minutes until smooth and creamy. 
13. Add confectioners' sugar, cream, vanilla extract and remaining vanilla bean seeds with mixer running. Increase to high speed and beat for 3 minutes. Add more powdered sugar if frosting is too thin or more cream if too thick. Add pinch of salt if too sweet.
14. For blue or red frosting, add coloring to white frosting, beating after each small addition, until you achieve desired color. 
15. Frost cooled cupcakes with pastry bag fitted with open star tip.
16. Store cupcakes in airtight container at room temperature for up to 3 days and in refrigerator for up to 7.

 To decorate: 

1. Using piping bag for each color of frosting, frost cupcakes: 12 blue, 18 red, 20 white.
2. To make white stars, use star tip and white frosting, or cut them out of white fondant.
3. Line up frosted cupcakes to form flag as follows, from left to right:

• Top row: 4 blue starred cupcakes, following by 4 red cupcakes
• Second row: 4 blue cupcakes, followed by 4 white cupcakes
• Third row: 4 blue cupcakes, followed by 4 red cupcakes
• Fourth rows: 8 white cupcakes
• Fifth row: 8 red cupcakes
• Sixth row: 8 white cupcakes
• Off to left and under flag, place two red cupcakes for Alaska and Hawaii.