Zesty Lemon Buttermilk Cake

1. Preheat Oven and Prepare Pan

First, adjust your oven rack to the middle position and preheat the oven to 325 degrees Fahrenheit. Grease and flour a 13- by 9-inch baking pan to ensure your cake doesn't stick.

2. Prepare Dry Mixture

In a medium bowl, whisk together the cake flour, baking powder, baking soda, and salt. This will be your dry mixture.

3. Prepare Wet Mixture

In a liquid measuring cup, combine the buttermilk, lemon juice, and vanilla extract. This will be your wet mixture.

4. Prepare Sugar Mixture

Using an electric mixer on medium speed, beat together the granulated sugar and grated lemon zest for about a minute. This will release the lemon oils, infusing the sugar with a zesty flavor. Once mixed, transfer 1/4 cup of this sugar mixture to a small bowl, cover it, and set it aside for later.

5. Cream Butter and Sugar

Add the softened butter to the remaining sugar mixture in the electric mixer bowl. Beat on medium speed for about 2 minutes until light and fluffy. This step is crucial for incorporating air into the batter, which will make your cake tender and airy.

6. Add Eggs and Egg Yolk

Beat in the eggs and egg yolk, one at a time, ensuring each is fully incorporated before adding the next.

7. Combine Mixtures

Now, on low speed, alternate adding the flour mixture and the buttermilk mixture to the batter, beginning and ending with the flour mixture. Mix just until smooth, which should take about 30 seconds.

8. Transfer to Pan

Scrape the batter into your prepared baking pan and smooth the top with a spatula.

9. Bake the Cake

Bake the cake for 25 to 35 minutes, until it is golden brown and a toothpick inserted into the center comes out clean. Once done, transfer the cake to a wire rack and let it cool in the pan for 10 minutes.

10. Prepare the Glaze

While the cake is cooling, prepare the glaze. In a bowl, whisk together the confectioners' sugar, lemon juice, and buttermilk until you have a smooth glaze.

11. Glaze the Cake

Spread the glaze over the warm cake and sprinkle the reserved lemon-sugar mixture evenly on top.

12. Cool Completely

Allow the cake to cool completely in the pan for at least 2 hours before serving. This will give the glaze time to set and the flavors to meld beautifully.