From http://nataliecakes.wordpress.com/2007/06/21/billys-vanilla-vanilla-cupcakes/

Ingredients

• 1 3/4 cups cake flour, not self-rising
• 1 1/4 cups unbleached all-purpose flour
• 2 cups sugar
• 2 tablespoons baking powder
• 3/4 teaspoon salt
• 1 cup unsalted butter, cut into 1-inch cubes
• 4 large eggs
• 1 cup whole milk
• 1 teaspoon pure vanilla extract

Preparation:
1. Preheat oven to 325°. Line cupcake pans with paper liners; set aside. In the bowl of an electric mixer fitted with the paddle attachment, combine flours, sugar, baking powder, and salt; mix on low speed until combined. Add butter, mixing until just coated with flour.
2. In a large glass measuring cup, whisk together eggs, milk, and vanilla. With mixer on medium speed, add wet ingredients in 3 parts, scraping down sides of bowl before each addition; beat until ingredients are incorporated but do not overbeat.
3. Divide batter evenly among liners, filling about two-thirds full.
4. Bake, rotating pan halfway through, until a cake tester inserted in the center comes out clean, 17 to 20 minutes.
5. Transfer to a wire rack to cool completely. Repeat process with remaining batter.