- 2 2/3 cups sugar
- 1 cup (2 stick) unsalted butter, cut into 1-inch pieces
- 2 large eggs
- 2 large egg yolks
- 2/3 cup milk
- 2/3 cup water
- 2 1/2 teaspoons pure vanilla extract
- 2 2/3 cups all-purpose flour
- 1 1/3 cups cake flour
- 4 teaspoons baking powder
- 1/2 teaspoon fine salt
Preheat oven to 350 degrees F. Line two 12-cup cupcake tins with paper liners. (To avoid cupcakes sticking if they overflow slightly, lightly spray the tops of the pans.) Put tins on a baking sheet. Set aside.
Process sugar and butter in a food processor until very creamy, scraping sides as needed, 1 to 2 minutes. Add the eggs and yolks, one at a time, pulsing after each addition. Add the milk, water, and vanilla and process to blend.
Whisk both flours, baking powder, and salt in a medium bowl. Add the dry ingredients, in 3 batches to the wet, pulsing, and then scraping batter off the sides of the processor as needed after each addition. Process until the batter is very smooth and pourable like pancake batter, about 2 minutes.
Evenly pour the batter into the prepared cups, filling them 3/4 of the way full. Bake until the cakes are just firm and spring back when gently pressed, and the tops are golden, 18 to 25 minutes. Cool slightly in tin, and turn out of tin when cool enough to handle. Cool cupcakes completely on a rack before frosting.