Yellow Buttermilk Cupcakes (makes 36)
3 cups cake flour
1 ½ cups all-purpose flour
¾ tsp baking soda
2 ¼ tsp baking powder
1 ½ tsp coarse salt
1 cup plus 2 tbsp (2 ¼ sticks) unsalted butter, room temperature
2 ¼ c sugar
5 large whole eggs plus 3 egg yolks, room temperature
2 cups buttermilk, room temperature
2 tsp vanilla extract
Preheat oven to 350. Line tins with wrappers.
Whisk together flours, baking soda, baking powder, and salt.
With an electric mixer on medium-high speed, cream butter and sugar until pale and fluffy. Reduce speed to medium and 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.
Divide batter evenly among 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 for 10 minutes, then turn out cupcakes and let cool completely. Cupcakes can be stored overnight at room temperature, or frozen for up to two months, in airtight containers.