Original Post: https://www.sweetandsavorybyshinee.com/lemon-layer-cake-with-lemon-swiss-meringue-buttercream/
Lemon Layer Cake
Servings: 12 servings
Calories: 636kcal
This lemon layer cake with lemon curd is wonderfully bright with a burst of lemon in every bite. Soft sponge cake layers soaked with lemon syrup and filled with homemade lemon curd and lemon Swiss buttercream frosting. It's bakery-worthy and fun to make with my tried-and-true method.
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Ingredients
Lemon sponge cake:
- 6 large eggs
- 1 cup (200 g) granulated sugar divided Note 1
- 2 tablespoons (30 g) fresh lemon juice Note 2
- 1 tablespoon lemon zest
- 1 ½ cups (180 g) cake flour sifted Note 3
- ½ teaspoon coarse kosher salt
Lemon Swiss Buttercream:
- 6 egg whites
- 1 ½ cups (300 g) granulated sugar
- 3 tablespoons (45 g) fresh lemon juice
- 1 ½ cups (340 g) unsalted butter sliced and at room temperature Note 4
- ½ teaspoon coarse kosher salt
Lemon Curd:
- 3 large eggs
- 1 cup (200 g) granulated sugar
- 1 cup (240 ml) fresh lemon juice
- 1 tablespoon lemon zest
- 5 tablespoons (70 g) unsalted butter sliced and at room temperature
Lemon Simple Syrup:
- ¾ cup (150 g) granulated sugar
- 2 tablespoons (30 g) fresh lemon juice
Instructions
To make the cake:
- Preheat the oven to 350°F (177°C). Line bottom of one 9-inch springform pan (at least 3 inches tall) with parchment paper. Do NOT grease the pan.
- Separate egg whites and yolks, making sure not even a little bit of egg yolk gets into the whites. (TIP: It’s easier to separate the egg when they’re cold right out of the fridge.)
- In a mixing bowl with a whisk attachment, whisk together egg yolks, ½ cup of sugar, lemon juice and lemon zest until pale and tripled in volume, about 5 minutes.
- In another mixing bowl with a whisk attachment, beat the egg whites at medium low speed until foamy. Add remaining ½ cup of sugar 1 tablespoon at a time and continue to whisk until stiff peaks, gradually increasing the speed to medium high, 7-10 minutes.
- Using a spatula, add 1/3 of the whipped egg whites into the egg yolk mixture and gently fold until mostly smooth. Add the remaining egg whites and gently fold until smooth.
- Add flour and salt into the batter in 3 stages, whisking the batter well after each addition.
- Pour the batter into the prepared pan and smooth the top.
- Bake the cake until inserted toothpick comes out clean, about 40 minutes. Don’t open the oven for at least the first 30 minutes!
- Let the cake cool for 5 minutes in the pan. Then run a knife around the edges and invert onto a cooling rack. Cool completely. Once cooled, wrap with plastic wrap and refrigerate, preferably overnight. It’ll be easier to slice it when the cake is thoroughly chilled.
To make the buttercream:
- In a small saucepan, bring a small amount of water to a boil. Reduce the heat to simmer.
- In medium heat-proof bowl (I used my stand mixer bowl), whisk together egg whites, sugar and lemon juice and place it over the saucepan with simmering water. (This is a make-shift double boiler. Make sure the bottom of the top bowl doesn’t touch the water.)
- Cook the egg white mixture until sugar is completely melted and it reaches 160°F (70°C) stirring continuously, about 5 minutes. (This's my favorite thermometer!)
- Now, remove the bowl with egg white mixture from heat. Then whisk it on medium speed for a minute, then slowly increase the speed to medium high and beat until stiff peaks form and the mixture is cool to touch, about 10 minutes. (It may take longer with a hand-mixer.)
- Once the meringue reached stiff peaks, scrape the side of the bowl with a spatula.
- Turn on the mixer on medium speed and start adding butter, one tablespoon at a time. Make sure the butter is fully incorporated before adding the next piece. (NOTE: It’s normal if buttercream starts to curlde half way. Keep adding the butter!)
- Keep whisking the buttercream until smooth, light and fluffy, about 10 minutes.
- Now, switch to a paddle attachment and add the salt. Beat the buttercream until well combined, about a minute.
- Transfer the buttercream into a large piping bag. You can use a round piping tip, if you have it, but it's not necessary.
To make the lemon curd:
- In a medium saucepan, whisk together eggs, sugar, lemon juice and lemon zest for a minute.
- Turn on the heat to low and cook the mixture, whisking constantly, until the mixture reaches 170°F (75°C), 8-10 minutes. The mixture will be thick and it'll leave a trail if you run a finger on back of spoon dipped in curd.
- Remove from heat and stir in butter.
- Place a mesh sieve over a bowl and run the curd through it. It makes the curd silky smooth!
- Cover the curd with plastic wrap, making sure it touches the curd to avoid forming a film. Cool completely and then refrigerate.
To make the syrup:
- In a small saucepan, bring 1 cup of water to a boil. Then stir in sugar and lemon juice. Once the sugar is fully dissolved, remove from heat and cool completely.
To assemble the cake:
- Slice the cake into 3 even layers. (This cake leveler is a handy tool for this job!)
- Smear a dollop of buttercream in the middle of a cake board and place the first cake layer on it. This will help your cake stay in place and won't slide.
- Generously brush on lemon syrup all over the cake layer. If you don't have a pastry brush, just use a regular spoon.
- Pipe a border with the buttercream around the edges of the cake and fill the middle with half of the lemon curd, if you're making 3-layer cake.
- Pipe more buttercream over the curd and evenly smear the frosting with an offset spatula. It's a bit tricky to level the buttercream over the curd, but piping the frosting makes this step super easy.
- Place the next cake layer and repeat the layers until all the layers are completed. (TIP: Place the top cake layer upside down so that the top of the cake is flat with sharp corners.)
- Then frost the entire cake with the remaining frosting. I ran a cake scraper on the sides for a naked-style finish. Decorate the cake any way you like. I smeared some lemon curd on top, piped dollops of buttercream frosting and sprinkled fresh lemon zest curls. I used this citrus zester tool to make those cute lemon zest curls. And my lemon macarons added an instant wow-factor as well!
Notes
Note 1: Fine granulated sugar or caster sugar is ideal for the cake recipe, as they dissolve quicker.
Note 2: You'll need about 6 lemons to make the entire recipe.
Note 3: Cake flour is highly recommend for a light and airy cake layers. In a pinch, substitute with a DIY cake flour: measure 1.5 cups of all purpose flour and replace 3 tablespoons of flour with 3 tablespoons of cornstarch. Sift it before using.
Note 4: Make sure the butter isn’t too soft. When you push a finger into it, the butter should dent with some resistance.
Make-Ahead Tip: You can make all the components of the cake separately up to 1 week in advance!
- Sponge cake can be made and frozen up to a month in advance, or refrigerated for up to a week. Thaw it in the fridge overnight.
- Swiss meringue buttercream can also be made and frozen for up to 3 months, or refrigerated for up to 2 weeks. Thaw the frozen buttercream on the counter overnight. Whip it before using.
- Lemon curd can be frozen for up to 2 months, or refrigerated for up to 2 weeks.
- Lemon syrup can also be made a week in advance. Refrigerate until ready to use.
Assemble the cake up to 1 day in advance and store it in the fridge, covered. Bring it out 1 hour prior to serving.
- Sponge cake can be made and frozen up to a month in advance, or refrigerated for up to a week. Thaw it in the fridge overnight.
- Swiss meringue buttercream can also be made and frozen for up to 3 months, or refrigerated for up to 2 weeks. Thaw the frozen buttercream on the counter overnight. Whip it before using.
- Lemon curd can be frozen for up to 2 months, or refrigerated for up to 2 weeks.
- Lemon syrup can also be made a week in advance. Refrigerate until ready to use.
Assemble the cake up to 1 day in advance and store it in the fridge, covered. Bring it out 1 hour prior to serving.
Nutrition
Calories: 636kcal
Carbohydrates: 84g
Protein: 8g
Fat: 31g
Sugar: 72g
Sodium: 174mg
