Yellow Buttermilk Cupcakes

Yellow Buttermilk Cupcakes:

Recipe from Martha Stewart's Cupcakes - makes 36:
3 cups cake four (not self-rising)
1 1/2 cups all-purpose flour
3/4 tsp baking soda
2 1/4 tsp baking powder
2 1/2 tsp coarse salt
1 cup plus 2 Tbsp unsalted butter, room temperature
2 1/4 cup sugar
5 large whole eggs PLUS 3 egg yolks, room temperature
2 cups buttermilk, room temperature
2 tsp pure vanilla extract
Fluffy Vanilla Frosting

1. Preheat oven to 350F.  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, about 20mins.  Transfer tins to wire racks to cool 10 minutes; turn out cupcakes onto racks and let cool completely.  Cupcakes can be stored overnight at room temp, or frozen up to 2 months, in airtight containers.

4. To finish, frost cupcakes.  Refrigerate up to 3 days in airtight containers.  Bring to room temp and if desired, decorate with sprinkles before serving.