Prep 1 hr
Cook 34 mins
- 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
- 3 cups powdered sugar
- 3 tablespoons fresh lemon juice
- 2 tablespoons buttermilk
- 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.