Ingredients:

  • 2.5 cups cake flour
  • 1.5 cups granulated sugar
  • 1 tbsp baking powder
  • 0.5 tsp salt
  • 0.5 cup unsalted butter, softened
  • 0.25 cup vegetable oil
  • 3 large eggs, room temperature
  • 2 large egg yolks, room temperature
  • 1 cup buttermilk, room temperature
  • 2 tsp pure vanilla extract
  • 1 cup unsalted butter, softened
  • 3.5 cups powdered sugar
  • 2 tbsp heavy cream
  • 1 tsp pure vanilla extract
  • 1 pinch salt

Instructions:

  1. Preheat oven to 350°F (175°C). Grease two 8-inch round cake pans and line the bottoms with parchment paper.
  2. Sift together cake flour, baking powder, and salt in a medium bowl.
  3. In a large bowl, cream softened butter and granulated sugar on medium-high until pale and fluffy (approximately 3 minutes), then stream in the vegetable oil while mixing.
  4. Add whole eggs and egg yolks one at a time, beating well after each addition until the batter is smooth and glossy.
  5. Reduce mixer speed to low. Add dry ingredients in three additions, alternating with buttermilk and vanilla extract (Dry, Wet, Dry, Wet, Dry), mixing only until flour streaks disappear.
  6. Divide batter evenly between the two pans and bake for 28–32 minutes or until a toothpick inserted comes out clean.
  7. Cool cakes in pans briefly before transferring to wire racks to cool completely (approximately 60 minutes).
  8. Prepare buttercream by creaming 1 cup unsalted butter, then gradually adding powdered sugar, heavy cream, vanilla extract, and a pinch of salt until smooth.
  9. Frost the cooled cake layers and assemble.