Ingredients:

  • 2 1/2 cups (300g) all-purpose flour, plus more for dusting the pan
  • 2 1/2 teaspoons baking powder
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1 cup (2 sticks/227g) unsalted butter, softened, plus more for greasing the pan
  • 1 3/4 cups (350g) granulated sugar
  • 2 large eggs
  • 1 large egg white
  • 1 tablespoon pure vanilla extract
  • 1 cup (240ml) buttermilk, room temperature
  • 1/2 cup (120ml) vegetable oil
  • 1 cup (2 sticks/227g) unsalted butter, softened
  • 3 cups (360g) powdered sugar, sifted
  • 1/4 cup (60ml) heavy cream
  • 1 tablespoon pure vanilla extract
  • Pinch of salt

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and flour two 9-inch round cake pans. Line the bottoms with parchment paper rounds.
  2. In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
  3. In a large bowl, cream together the softened butter and granulated sugar until light and fluffy.
  4. Beat in eggs and egg white one at a time, then stir in the vanilla extract.
  5. Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk and vegetable oil, beginning and ending with the dry ingredients. Mix until just combined.
  6. Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.
  7. Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.
  8. While the cakes are cooling, prepare the vanilla buttercream frosting. In a large bowl, beat the softened butter until light and fluffy. Gradually add the powdered sugar, beating until smooth. Add the heavy cream, vanilla extract, and salt, and beat until light and fluffy.
  9. Once the cakes are completely cool, level the tops if needed. Place one cake layer on a serving plate, frost with buttercream, top with the second cake layer, and frost the entire cake.
  10. Chill the frosted cake for at least 30 minutes before serving.