Step 1

Important Things To Note Before You StartBring all your ingredients to room temperature or even a little warm (eggs, buttermilk, butter, etc) to ensure your batter does not break or curdle. Use a scale to weigh your ingredients (including liquids) unless otherwise instructed (Tablespoons, teaspoons, pinch etc). Metric measurements are available in the recipe card. Scaled ingredients are much more accurate than using cups and help ensure the success of your recipe. Practice Mise en Place (everything in it's place). Measure out your ingredients ahead of time and have them ready before you start mixing to reduce the chances of accidentally leaving something out.Chill your cakes before frosting and filling. You can cover a frosted and chilled cake in fondant if you wish. This cake is also great for stacking. I always keep my cakes chilled in the refrigerator before delivery for easy transporting.

Step 2

Preheat your oven to 335º F/168º C Prepare your cake pans with cake goop or another pan release. For square pans or cakes over 12', I also use parchment paper.

Step 3

Combine the 4oz of buttermilk with the oil and set aside.

Step 4

To the remaining 6oz of buttermilk, add your eggs, lemon zest, lemon extract, and lemon juice. Whisk lightly to break up the eggs and set aside.

Step 5

Place cake flour, sugar, salt, baking powder, and baking soda into the bowl of your stand mixer with the paddle attachment attached.

Step 6

Turn the mixer onto the lowest speed. Add in your softened butter in small chunks mix until the flour mixture resembles coarse sand.

Step 7

Add your oil/milk mixture all at once to the dry ingredients and mix on medium (speed 4 on KitchenAid) for 2 full minutes to develop the cake's structure.

Step 8

Scrape the bowl. This is an important step. If you skip it, you will have hard lumps of flour and unmixed ingredients in your batter. If you do it later, they will not mix in fully.

Step 9

Slowly add in the milk/egg mixture in 3 parts, letting the batter mix for 10 seconds between additions. Stop to scrape the bowl once more halfway through. Your batter should be thick and not separated. If it is separated, some of your ingredients could have been too cold or you added your liquids too quickly.

Step 10

Fill your cake pans 3/4 full with cake batter. Give the pan a little tap on each side to level out the batter and get rid of any air bubbles. You can also weigh your cake pans to ensure that each pan has the same amount of cake batter.

Step 11

Smaller cakes will bake faster than larger cakes. Start with 30 minutes for 6' or 8' cakes and add time as needed. Each oven is different so adjust your baking time as needed. Cakes are baked when a toothpick comes out cleanly from the center. Remove cakes from the oven and give them a tap on the countertop to release air and prevent too much shrinking.

Step 12

After cakes have cooled for 10 minutes or the pans are cool enough to touch, flip the cakes over onto a cooling rack and let cool until barely warm. Wrap your cakes in plastic wrap and chill in the refrigerator before frosting so they are easier to handle. You can also put them in the freezer if you are in a hurry for them to cool down.

Step 13

Once the cakes are chilled you can now trim, fill and decorate your cake as you wish.

Step 14

Bring about a ½” to 1” of water to a boil in a large saucepan

Step 15

In a large glass bowl or non-reactive metal bowl whisk together the egg yolks, lemon juice, zest, sugar, and salt. Place the bowl over the saucepan.

Step 16

Bring the water to a simmer and whisk the mixture constantly until it thickens and them temperature reads about 170ºF.

Step 17

Whisk together the cornstarch and water to make a slurry, add it into the bubbling mixture, stirring constantly and cook for 1-2 more minutes until the cornstarch is clear.

Step 18

Remove the curd from the heat. Immediately add your butter in small pieces to the curd. Whisk until it until its smooth. Strain the mixture to remove any large pieces of zest or seeds.

Step 19

Cover the curd with plastic wrap so that it is touching the surface of the curd without any air bubbles in between, this will prevent a skin from forming on the top of the curd. Refrigerate until cool before using.

Step 20

Place egg whites and powdered sugar in a mixing bowl with the whisk attachment. Whisk on high 2-3 minutes to combine.

Step 21

Add in butter in small chunks then lemon extract and salt. Whip on high until light and fluffy and white. Add in your lemon curd and mix to combine.Optional: switch to the paddle attachment and mix on low for 15-20 minutes until all air bubbles are gone.