Ingredients:

  • 225g (1 cup) unsalted butter, softened, plus extra for greasing the pans
  • 170g (6 ounces) high-quality white chocolate, chopped
  • 225g (1 cup plus 2 tablespoons) granulated sugar
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 280g (2 1/4 cups) all-purpose flour
  • 1 1/2 teaspoons baking powder
  • 1/4 teaspoon salt
  • 240ml (1 cup) milk
  • 60ml (1/4 cup) vegetable oil
  • 225g (1 cup) unsalted butter, softened
  • 450g (4 cups) powdered sugar, sifted
  • 170g (6 ounces) high-quality white chocolate, melted and cooled slightly
  • 3-4 tablespoons milk or heavy cream
  • 1 teaspoon vanilla extract

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and flour the cake pans. Line the bottoms with parchment paper rounds.
  2. Combine white chocolate and butter in a microwave safe bowl. Melt, stirring occasionally, until smooth. Let cool slightly but not solidify.
  3. In a large bowl, cream together the softened butter and sugar until light and fluffy.
  4. Beat in the eggs one at a time, then stir in the vanilla extract.
  5. In a separate bowl, whisk together the flour, baking powder, and salt.
  6. Gradually add the dry ingredients to the wet ingredients, alternating with the milk and oil, beginning and ending with the dry ingredients. Mix until just combined. Don't overmix!
  7. Gently fold the cooled white chocolate and butter mixture into the batter until evenly distributed.
  8. 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.
  9. Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.
  10. In a large bowl, beat the softened butter until smooth and creamy. Gradually beat in the powdered sugar until combined.
  11. Beat in the melted and cooled white chocolate, vanilla extract, and enough milk or cream to reach a smooth, spreadable consistency.
  12. Once the cakes are completely cool, level them with a serrated knife if necessary. Place one cake layer on a serving plate, top with frosting. Add the second cake layer and frost the entire cake.
  13. Chill the frosted cake for at least 30 minutes to allow the frosting to set. (Optional, but helps with clean slicing).