Prep oven and pans. Position rack in the center of your oven and preheat the oven to 350° F (180°C). Line a cupcake pan with paper liners. Set aside.
Combine dry ingredients. In a medium mixing bowl, combine the cake flour, baking powder and salt. Whisk together and set aside.1 1/4 cups (150g) cake flour 1 1/4 teaspoons baking powder 1/4 teaspoon salt
Cream butter and sugar Cream together the butter and sugar to the bowl of an electric mixer fitted with the paddle attachment. Beat on medium-high speed for 3 minutes, until light and fluffy in color. Scrape down the sides of the bowl. 1/2 cup (1 sticks, 113 g) unsalted butter 3/4 cup (150 g) granulated sugar
Add eggs and vanilla. Mix in the eggs one at a time until incorporated. Scrape down the sides of the bowl after each addition. Add vanilla and beat to combine. 2 large eggs 1 Tablespoon vanilla extract
Alternate dry ingredients with buttermilk. With the mixer on low speed, add the dry ingredients alternately with the buttermilk, beginning and ending with the dry ingredients and mixing just until incorporated. Scrape down the sides of the bowl and mix for 15 seconds longer.1/2 cup (120 ml) buttermilk
Bake cupcakes. Divide the batter between the prepared paper liners, filling each about 2/3 of the way full. Bake 18-20 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool in the pans 5-10 minutes, then transfer to a cooling rack to cool completely before frosting.