Ingredients

  • Cake
  • 2 1/2 cups cake flour
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon salt
  • 3/4 cup buttermilk, room temperature
  • 1/4 cup fresh lemon juice
  • 3 tablespoons grated fresh lemon zest (about 3 lemons)
  • 1 teaspoon vanilla extract
  • 1 3/4 cups sugar
  • 12 tablespoons unsalted butter, softened (1 1/2 sticks)
  • 3 large eggs, room temperature
  • 1 large egg yolk, room temperature
  • Glaze
  • 3 cups powdered sugar
  • 3 tablespoons fresh lemon juice
  • 2 tablespoons buttermilk

Method

  • Cake: position oven rack in middle position; preheat to 325°.
  • Grease and flour a 13 x 9 inch baking pan.
  • In a bowl, combine the flour, baking powder, baking soda, and salt.
  • In a liquid measuring cup, combine the buttermilk, lemon juice, and vanilla.
  • In a big bowl, beat together the sugar and lemon zest with an electric mixer on medium speed, until moist and fragrant, about 1 minute.
  • Transfer 1/4 cup of sugar mixture to a small bowl, cover, and reserve.
  • Add the butter to the remaining sugar mixture and beat until light and fluffy, about 2 minutes.
  • Beat in the eggs, one at a time, and the yolk until combined.
  • Decrease mixer speed to low.
  • Mix in 1/3 of the flour mixture, followed by half of the buttermilk mixture.
  • Repeat with half the remaining flour mixture and the remaining buttermilk mixture.
  • Add the remaining flour mixture and mix until smooth, about 30 seconds.
  • Give the batter a final stir with a rubber spatula to make sure it is thoroughly combined.
  • Scrape the batter into the prepared pan, smooth the top, and gently tap the pan on the work surface to settle the batter.
  • Bake until the cake is golden brown and a pick comes out clean, about 28-34 minutes, rotating the pan halfway through baking.
  • Transfer pan to a wire rack and let the cake cool for 10 minutes.
  • Glaze: meanwhile, whisk the glaze ingredients together until smooth.
  • Gently spread the glaze over the warm cake and sprinkle evenly with the reserved sugar mixture.
  • Cool completely, at least 2 hours, then serve.