Step 1

Make the lemon curd first so that it has time to cool and thicken. Separate 6 yolks from the whites and set aside the egg whites to make the Swiss meringue buttercream later. Make sure the eggs are cold when you separate them; it makes the process easier.

Step 2

Add 1 cup of sugar into a small saucepan. One quick thing to note! When making the lemon curd, it's best to use a saucepan that's ceramic as opposed to metal. Some metal pans and sometimes even metal whisks can give the curd a metallic taste.

Step 3

Zest 2 lemons into the saucepan and massage the zest into the sugar with your fingertips. This helps release the oil in the zest and gives this curd a bright, citrusy flavor.

Step 4

Add in 6 egg yolks and whisk the mixture together until combined. Then mix in the juice of 1/2 cup of fresh lemon juice.

Step 5

Heat on medium-low, stirring constantly with a wire whisk until the mixture thickens. It should be thick enough to coat the back of a spoon and keep its shape. This usually takes me 5-7 minutes.

Step 6

Remove the pan from heat, then add in 1/2 cup of cold butter that's been cut into smaller pieces. Mix until the butter is fully melted, and the ingredients are combined.

Step 7

Pour the lemon curd through a fine mesh strainer into a separate bowl to remove any bits of cooked egg, clumps of zest, or lemon seeds. This gives it a perfectly smooth texture! Set aside to cool. If you make the curd in advance, cover it flush with plastic wrap to prevent it from forming a skin and store in the fridge for up to a month.

Step 8

Then it's time for the cake layers! Preheat the oven to 350°F/175°C and line and grease three, 8-inch cake pans with parchment rounds and non-stick spray.

Step 9

Add 3 cups sugar and zest 2 large lemons into a large bowl or the bowl of a stand mixer. Use your fingertips to massage the zest into the sugar to help release the oil in the zest.

Step 10

Add 3 cups cake flour, 2 1/2 tsp baking powder, and 1 tsp salt into the bowl with the sugar and whisk together until combined.

Step 11

Then mix in 1 cup (2 sticks) of unsalted butter with a paddle attachment or hand mixer on a low speed. Continue to mix until no large chunks of butter remain, and the mixture looks like moist sand.

Step 12

Mix in 1 cup of egg whites on a medium speed until incorporated. The batter should be quite thick at this point.

Step 13

Then add in 1 1/2 cups buttermilk, 2 Tbsp vegetable oil, and 1 tsp vanilla extract. Mix on a low speed until incorporated.

Step 14

Scrape down the sides and bottom of the bowl with a rubber spatula, then beat on medium speed for about 30 seconds to make sure everything is properly mixed together. This cake recipe uses the reverse creaming method, so this step is important to help give the cake layers a lighter texture.

Step 15

Pour half of the cake batter (about 900g) into a separate bowl. Use a small drop of gel food coloring to color one bowl of batter light yellow.

Step 16

Alternate pouring the uncolored and yellow batter into the prepared pans to give the cake layers a marbled look. Use a butter knife or a small offset spatula to swirl the batter together. Bake for 33-36 minutes or until a toothpick comes out with a few moist crumbs. Let the cake layers cool in the pans for 15 minutes, then run a small offset spatula around the perimeter of the pan to separate the cake from the pan.

Step 17

Flip the cake layers onto a wire rack to cool. Use a serrated knife to level the tops and remove the caramelization around the sides of the layers. I also like to torte the cake layers horizontally (see picture above) to create 6 thinner cake layers, but this is optional. You can also trim the layers, then wrap and freeze them if you're making them in advance.

Step 18

If you make these cake layers in advance and freeze them, let them thaw for about 20 minutes before assembling your cake. The cake layers should still be cold to the touch, which will make it easier to assemble your cake.

Step 19

While the cake layers bake and cool, make the lemon buttercream frosting.

Step 20

Before making the frosting, be sure to thoroughly clean your mixing bowl. If there’s any grease it can make it difficult to whip up the meringue.

Step 21

In a medium sized pot, add 1 inch of water and bring to a simmer.

Step 22

Add 8 egg whites (use the 6 egg whites saved from making the lemon curd, plus two additional egg whites) and 2 1/2 cups of granulated sugar into a large metal bowl.

Step 23

Place the bowl on top of the pot filled with simmering water. The bowl should create a seal over the pot. Make sure the water isn’t actually touching the bottom of the bowl, or it can cook the egg whites.

Step 24

Whisk the mixture constantly for about 3 minutes, until it reaches 160°F / 71°C. You can test the mixture to see if it’s ready by rubbing a tiny bit between your fingertips. The sugar should be fully dissolved, and it should feel super smooth and hot to the touch.

Step 25

Lift the bowl away from the pot and dry the bottom with a towel. Pour the mixture into the bowl of a stand mixer and beat on a medium-high speed with a whisk attachment. Mix for about 10 minutes, or until you have stiff, glossy peaks.

Step 26

Mix in 2 cups of unsalted butter at a medium speed, 1 stick at a time. The frosting should have a thick, whipped consistency at this point. If it looks lumpy or broken, keep mixing until it looks smooth and thick. If it doesn't seem to come together after an additional 10 minutes of mixing, check out my Swiss meringue buttercream troubleshooting guide.

Step 27

Once the consistency is right, swap out the whisk attachment for a paddle attachment and add in the zest of 2 large lemons, 1/4 cup fresh lemon juice, 2 tsp vanilla extract, 2 tsp lemon extract, and 1/2 tsp fine salt.

Step 28

To make the frosting extra smooth, swap out the whisk attachment for a paddle attachment and continue mixing on a low speed for a couple minutes.

Step 29

Place half of the frosting in a large piping bag and cut a 1-inch opening at the base of the bag. Set aside.

Step 30

Stack and frost the cake layers on a greaseproof cake board or flat plate using a dab of frosting to help stick the first cake layer to the board.

Step 31

Spread a thin layer of buttercream on top of each cake layer. Pipe a thick ring of buttercream around the edge of the cake layer and fill the center with lemon curd. I like to add about 1/3 cup of lemon curd between each layer. Make sure you reserve about 1/4 cup of lemon curd to decorate the cake later. Note: If you torte the layers like I did, alternate filling the cake with layers of lemon curd and a thick layer of frosting.

Step 32

Once all the layers are stacked, gently press down on top of the cake with both of your hands to help them settle and to press out any trapped air between the cake layers.

Step 33

Chill the cake in the freezer for 5-10 minutes to prevent the layers from sliding, then add a thin coat of frosting around the cake that fully covers the cake layers. Smooth using a large offset spatula and/or bench scraper, then chill the cake again in the fridge (30 minutes) or freezer (10 minutes) until the frosting is firm to the touch.

Step 34

Then add a second layer of frosting to the cake with the remaining buttercream. Use a large offset spatula to give the frosting a textured look. Use a small offset spatula to add swipes of lemon curd around the cake and blend it into the frosting. Then decorate as desired and enjoy! I added some dried lemon slices as a garnish.