1. Yellow Buttermilk Cupcakes: Preheat oven to 350 degrees. Line standard muffin tins with paper liners. Sift together both flours, baking soda, baking powder, and salt.

2. With an electric mixer on medium-high speed, cream butter and sugar until pale and fluffy. Reduce speed to medium. Add whole eggs, one at a time, beating until each is incorporated, scraping down sides of bowl as needed. Add yolks, and beat until thoroughly combined. Reduce speed to low. Add flour mixture in three batches, alternating with two additions of buttermilk, and beating until combined after each. Beat in vanilla.

3. Divide batter evenly among lined cups, filling each three-quarters full. Bake, rotating tins halfway through, until cupcakes spring back when lightly touched and a cake tester inserted in centers comes out clean, about 20 minutes. Transfer tins to wire racks to cool 10 minutes; turn out cupcakes onto racks and let cool completely. (Cupcakes can be frozen up to 2 months, in airtight containers.)

4. Swiss Meringue Buttercream: Combine egg whites, sugar, and salt in a heatproof bowl of a standing mixer set over a pan of simmering water. Whisk constantly by hand until mixture is warm to the touch and sugar has dissolved (the mixture should feel completely smooth when rubbed between your fingertips).

5. Attach the bowl to the mixer fitted with the whisk attachment. Starting on low and gradually increasing to medium-high speed, whisk until stiff (but not dry) peaks form. Continue mixing until the mixture is fluffy and glossy, and completely cool (test by touching the bottom of the bowl), about 10 minutes.

6. With mixer on medium-low speed, add the butter a few tablespoons at a time, mixing well after each addition. Once all butter has been added, whisk in vanilla. Switch to the paddle attachment, and continue beating on low speed until all air bubbles are eliminated, about 2 minutes. Scrape down sides of bowl with a flexible spatula, and continue beating until the frosting is completely smooth. Keep buttercream at room temperature and beat with paddle attachment on low speed until smooth again, about 5 minutes.

7. Decorating: Tint 1 cup buttercream bright blue with gel-paste food color. Transfer to a pastry bag fitted with a small plain tip (#4). Using an offset spatula, spread each cupcake with a smooth layer of untinted buttercream. (Cupcakes can be refrigerated up to 3 days in airtight containers; bring to room temperature before decorating.)

8. To finish, cut licorice laces into seventy-two 1 1/2-inch-long pieces and seventy-two 3/4-inch-long pieces. Arrange three longer pieces and three shorter pieces to form a flag pattern on each cupcake. With blue frosting, pipe nine dots in each open corner to form "stars."