Skip to Content

Luscious Lemon Mousse Cake – Layer cake perfection

Luscious lemon mousse cake might be the perfect layer cake. Lemon cake with Limoncello syrup, zesty lemon curd and creamy lemon mousse. (Limoncello liquor is optional.)

A lemon layer cake on a glass cake stand.

I am so excited to share this recipe with you! For many years this was the most popular cake flavor for my custom cake business. Once I introduced the Chocolate Chip Cookie Cake the two cake flavors shared top billing.

For the last 5 years I’d say almost half the wedding cakes I sold had two different flavors in the cake; half the servings with the cookie flavor, and the other half with Luscious Lemon Mousse Cake. And this cake is truly luscious!

Yes, this cake is a little bit of a project. But I think it’s totally worth the effort, especially for a special occasion.

If you watch the video you’ll see the entire process. It is sped up, but you can see how easily the whole thing comes together once you have all the components in place.

a lemon layer cake on a glass cake stand

How to make a great Lemon Mousse Cake:

The step that might be the most unfamiliar to non-pastry-chefs is how to “liason” or “temper” the gelatin into the mousse.

Tempering gelatin is similar to the process for tempering eggs into hot milk to make custard.

If you simply poured the warm gelatin into the cool mousse it might immediately set into little rubbery lumps. Definitely not the texture we’re going for here.

By whisking a scoop of mousse into the melted gelatin we bring the two ingredients closer together in texture and temperature. Now we have silky-smooth mousse. The filling is set with just enough gelatin to hold it together when the cake is sliced.

a slice of lemon mousse cake on a glass plate with a fork

The limoncello makes the flavor extra special. Of course, if you can’t or don’t want to do liquor you can leave it out. You can use water to bloom the gelatin.

But even if you generally aren’t a fan of liquor flavors I suggest you give it a try. The limoncello adds a deep lemon flavor without leaving a boozy aftertaste. You can check out this post to see why alcohol enhances flavor.

a partially eaten slice of lemon mousse layer cake on a glass plate with a fork

This cake recipe incorporates several other recipes. There is no need to reinvent my cake and buttercream recipes every time I come up with a new flavor. I just flavor them to whichever cake I’m putting together. All the recipes listed are included at the end of this post.

Watch the recipe video to see how-to make a Luscious Lemon Mousse Cake from start to finish.


If you love great cake recipes, you’ll love my new book: Easy Baking From Scratch: Quick Tutorials, Time-Saving Tips, Extraordinary Sweet and Savory Classics. The book contains over 100 recipes that have been well-tested and are presented in simple, clear language. It’s available now on Amazon.

Want to learn more about how I create my cake recipes? This post has lots of great information about baking science and how to perfect any recipe.


 

If you love this recipe as much as I do, I’d really appreciate a 5-star review.

luscious lemon mousse cake

Luscious Lemon Mousse Cake

Yield: 16-20 servings
Prep Time: 1 hour
Bake Time: 35 minutes
Chilling Time: 4 hours
Total Time: 5 hours 35 minutes

Luscious lemon mousse cake might be the perfect layer cake. Lemon cake with Limoncello syrup, zesty lemon curd and creamy lemon mousse. (Limoncello liquor is optional.)

Ingredients

Cake

  • 1 recipe Vanilla Butter Cake
  • Grated zest from 1 lemon
  • 2 teaspoons lemon extract

Lemon Mousse

  • 3 tablespoons (1.5 oz, 44ml) Limoncello (use water if you want to avoid alcohol)
  • 1 teaspoon lemon extract
  • 1 1/2 teaspoons gelatin powder
  • 1 cup (8 oz, 236ml) heavy cream
  • 2 tablespoons powdered sugar
  • 1 1/4 cups Lemon Curd

Assembly

  • 1 Recipe Italian Meringue Buttercream (or your favorite buttercream) flavored to taste with lemon extract, lemon zest and Limoncello
  • 1 Recipe Simple Syrup flavored with 1/4 cup Limoncello (or to taste) or 1 teaspoon lemon extract
  • 1 3/4 cups (16 oz, 455 g) Lemon Curd

Instructions

Cake

  1. Mix the cake according to the recipe, adding the zest to the dry ingredients and the lemon extract with the vanilla.
  2. Divide the batter between two 8" pans lined with a parchment round or buttered and floured. Bake as instructed in the recipe. Wrap the cooled layers and chill until firm (I like to bake the cake a day ahead)
  3. When you're ready to assemble the cake, trim the browned edges and domed top off both cakes. Split each cake horizontally so you have a total of 4 cake layers. See how to prep the layers here. Have your syrup and buttercream ready before you begin making the Lemon Mousse.

Lemon Mousse

  1. Place the Limoncello (or cold water) and lemon extract into a microwave safe bowl. Sprinkle the gelatin over the liquid in an even layer. Whisk briefly to combine and set aside to bloom. Whip the cream with the powdered sugar and set aside.
  2. Place the 1 1/4 cups lemon curd in a large mixing bowl and use a spatula to smooth out the curd to break up any lumps. Fold 1/3 of the the cream into the lemon curd until no lumps of curd remain. Fold in the remaining cream until it's about 1/2 way incorporated.
  3. Heat the bloomed gelatin in the microwave in 10 second increments until it's hot to the touch. Working quickly, add a 1/2 cup of the mousse to the warmed gelatin. Whisk immediately until completely incorporated. Pour the gelatin mixture back into the mousse. Immediately whisk until the mousse is smooth and the gelatin is evenly incorporated. If the mousse is very soft, refrigerate briefly to let it thicken before assembling the cake.

Assembly

  1. Fill a piping bag fitted with a star tip with buttercream (or use a disposable bag with the tip cut).
  2. Set one layer of the cake, flat side down, onto a cardboard cake round or a serving plate. Brush the layer generously with the Limoncello syrup. Pipe a ring of buttercream around the edge of the layer to form a "dam" for the mousse. Scoop half the lemon mousse onto the layer and smooth until even.
  3. Gently place the second cake layer onto the mousse, careful not to squish the mousse layer. Brush the layer with syrup and pipe a dam of buttercream. Set aside a 1/2 cup of the lemon curd and scoop the rest onto the layer. Smooth the curd until even (be careful not too press hard or you might squish the mousse layer beneath).
  4. Place the 3rd cake layer, brush with syrup and pipe a dam. Fill with the remaining lemon mousse. Top with the 4th layer, brush with syrup. Set the cake into the refrigerator for about 20 minutes to set the buttercream "dams" and the mousse.
  5. Ice the cake with a thin crumb coat of buttercream. Refrigerate the cake for at least an hour to set the buttercream and allow the mousse time to gel. Ice the cake with a final coating of buttercream.
  6. Use a piping bag fitted with a star tip to pipe a border around the top of the cake. Spread the last 1/2 cup of curd onto the cake. Refrigerate for at least 3-4 hours to make sure the filling is completely set, preferably over night.
  7. Remove the cake from the refrigerator 1/2 hour before serving.

Notes

The cake must be stored in the refrigerator because of the mousse filling. Take the cake out 1/2 hour to an hour before serving to allow it to soften before serving. Leftovers can be refrigerated and the cake freezes very well.

Did you make this recipe?

Please leave a comment on the blog or share a photo on Instagram

A four layer Vanilla cake on a white cake stand.

Vanilla Butter Cake

Yield: 12-16 servings
Prep Time: 30 minutes
Bake Time: 30 minutes
Total Time: 1 hour

Perfectly tender and buttery vanilla cake layers. Super soft, yet strong enough for sculpted or wedding cakes.

Ingredients

  • 6 large egg yolks at room temperature
  • 1 cup (8 oz, 224g) sour cream at room temperature, divided
  • 1 tablespoon vanilla extract
  • 2 cups (9 oz, 255g) cake flour
  • 1 1/2 cups (12 oz, 340g) granulated sugar, 1/4 cup separated
  • 3/4 teaspoon baking powder
  • 3/4 teaspoon salt
  • 1/4 teaspoon baking soda
  • 2 sticks + 2 tablespoons (9 oz, 255g) unsalted butter at room temperature
  • 3 large egg whites at room temperature

Instructions

  1. Preheat the oven to 350°F. Line two 8" round cake pans with a circle of parchment paper or butter and flour the bottom of the pans only, not the sides.
  2. Combine the yolks, 1/2 the sour cream and the vanilla in a small bowl, whisk to combine, set aside.
  3. Into a mixer bowl put 1 1/4 cups of the sugar, sift in the flour, leavening and salt. Mix on low speed for 10 seconds to distribute the leavening. Add the butter to the flour mixture. Mix on low until the butter is incorporated and the batter looks like a paste. Add the other 1/2 of the sour cream to the flour and butter mixture. Increase the speed to medium and mix about 3 minutes until the batter lightens in texture. If you're using a hand mixer add another minute or two to the total time.
  4. Scrape the sides and bottom of the bowl. With the mixer on low, add 1/2 the egg yolk mixture. Mix until mostly incorporated. Scrape the sides and bottom of the bowl. Add the rest of the egg yolk mixture. Scrape the bowl and mix until incorporated.
  5. In another bowl, whip the egg whites on medium high until they form soft peaks. Turn the mixer to medium low and slowly add the remaining 1/4 cup of sugar. Turn the mixer to medium high and whip the whites to full peak. Fold the whites into the base in 2 parts, folding just until there are no streaks of egg whites.
  6. Divide the batter between the 2 pans and spread so it's level.
  7. Bake until the center of the cake springs back when lightly pressed or a toothpick inserted into the middle of the cake comes out clean, about 25-30 minutes.
  8. Cool 10 minutes in the pan and then turn out onto a cooling rack. When fully cooled, wrap in plastic and refrigerate at least 3 hours or overnight before filling and assembling the cake.

Notes

The cake is very soft the day that it's baked. If you'd like to trim the crust and split the layers allow it to chill in the refrigerator until it's firm enough to handle without breaking. The filled cake can be kept at room temperature for several days (unless it has a perishable filling). The cake cake be frozen for several months.

Did you make this recipe?

Please leave a comment on the blog or share a photo on Instagram

a jar of lemon curd

Perfect Lemon Curd

Yield: 3 cups
Prep Time: 15 minutes
Cook Time: 10 minutes
Total Time: 25 minutes

Lemon curd is an incredibly easy to make recipe that is unbelievably versatile in the kitchen. Use curd for a spread on scones, as a tart filling, a cake filling or the base for a feathery lemon mousse.

Ingredients

  • 1 1/2 teaspoons gelatin powder (optional)
  • 1 1/2 cups (12 oz, 336g) granulated sugar
  • 3 eggs
  • 1/2 cup (4 oz, 120ml) lemon juice from about 3-4 lemons
  • Finely grated zest from all the lemons
  • Pinch of salt
  • 6 tablespoons (3 oz, 84g) unsalted butter, cut into 1" chunks

Instructions

  1. If you are using the gelatin, bloom in 2 tablespoons cold water in a medium size bowl. Set aside.
  2. Thoroughly whisk together the sugar and eggs in a medium saucepan. Add the lemon juice, zest and salt.
  3. Place the butter on top of the bloomed gelatin. Put a fine mesh sieve over the bowl and keep it near the stove.
  4. Heat the egg/juice mixture over medium low heat, stirring constantly. You must be sure to keep stirring across the entire bottom and corners of the pot so the custard does not have a chance to stick. The mixture will start out opaque with a fine white foam over the surface. As it heats up the curd will thicken, become more translucent and the foam will disappear.
  5. Cook until the curd will coat the back of a wooden spoon and just begins to boil. Don't allow it to come to a rolling boil. One or two bubbles is all you need to see.
  6. Immediately remove from the heat and pour through the sieve over the butter and gelatin. You can skip straining the curd if you like the bits of zest in the curd.
  7. Stir until the butter and gelatin are melted and thoroughly incorporated. Cover the bowl with plastic wrap and cool a bit before putting in the refrigerator.
  8. Refrigerate until completely cooled. If using gelatin, allow it to sit 8 hours or overnight to gel.

Notes

Lime, Orange, Blood Orange, Pink Grapefruit,

  1. 1/2 cup of juice (about 3-4 limes, 2-3 oranges, 1 grapefruit)
  2. 1 1/4 cup (10 oz) granulated sugar
  3. Zest from the fruits

Recommended Products

As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.

Did you make this recipe?

Please leave a comment on the blog or share a photo on Instagram

Italian Meringue Buttercream

Italian Meringue Buttercream

Yield: 16 servings
Prep Time: 20 minutes
Cook Time: 10 minutes
Total Time: 30 minutes

Light, fluffy and not too sweet, Italian Meringue Buttercream is a dream to work with. It takes on almost any flavor and is strong enough to pipe roses and other decorations.

Ingredients

  • 1/4 cup (60 ml) water
  • 1 cup (8 oz, 226g) granulated sugar, divided
  • 5 large (6 oz, 170g) egg whites, at room temperature (see note 1)
  • Pinch of salt
  • 1 pound unsalted butter (453g) room temperature, cut into 16 pieces
  • 1 tablespoon real vanilla extract
  • Other flavorings to taste

Instructions

  1. Combine the water with 3/4 cup granulated sugar in a small saucepan. Cook the sugar syrup on medium high heat, stirring until the sugar is melted. Once the syrup begins to boil do not stir the syrup. Allow it to cook to 235°-240°F (soft ball stage).
  2. While the syrup is boiling, whip the whites on medium high speed. When the whites are at soft peak reduce the mixer to medium low and slowly add the remaining 1/4 cup of sugar and a pinch of salt. Increase the speed to medium high and whip to full peak.
  3. As soon as the syrup is at the correct temperature, remove the pan from the heat. With the mixer running on medium low, pour the hot syrup in a steady stream between the edge of the bowl and the whisk. Increase the speed to medium high and continue whisking until the whites are cooled to about 80°F.
  4. When the whites have cooled, with the mixer running on medium, add the butter one piece at a time. Add the vanilla and increase the speed to medium high and whip until the buttercream comes together.
  5. Store at room temperature until ready to use.

Notes

Note 1: I always use fresh egg whites. If you use pasteurized egg whites from a carton make sure the package says they can be used for meringue. Some markets sell pasteurized eggs still in the shell, those can also be used for this recipe.

If the buttercream becomes "spongy" while standing re-whisk to correct the texture. The buttercream can be refrigerated 3-4 days or frozen for several weeks.

Return to room temperature and re-whisk before using.

Did you make this recipe?

Please leave a comment on the blog or share a photo on Instagram

Simple Syrup

Simple Syrup

Yield: 3/4 cup
Prep Time: 5 minutes
Cook Time: 5 minutes
Total Time: 10 minutes

Simple syrup is a pastry kitchen staple. Use it to add a layer of flavor to your favorite cake or stir it into iced tea or a cocktail.

Ingredients

  • 1/2 cup (4 oz, 125 ml) water
  • 1/3 cup (3 oz, 85g) granulated sugar
  • liquor of choice to taste (I would use about 2 tablespoons)

Instructions

  1. Combine the sugar and water in a small saucepan
  2. Heat over medium high heat just until all the sugar is melted
  3. Remove from heat and allow to cool completely before adding the liquor/flavoring.

Notes

The simple syrup can be stored in the refrigerator for several weeks.
Without the added liquor, this syrup is also great for sweetening iced tea or lemonade.

Did you make this recipe?

Please leave a comment on the blog or share a photo on Instagram

a juice burger on a plate
Previous
Milk & Honey Whole Wheat Hamburger Buns
a hand holding a rhubarb fritter
Next
Rhubarb Fritters with Cardamom & Grains of Paradise

Lindsey Miller

Friday 2nd of April 2021

Hi Eileen! I'm so excited to make this cake for Easter. When making the lemon curd can i use the limoncello to bloom the gelatin instead of water? Also, when you put the butter in with the gelatin is it melted or room temp butter? Will the heat of the lemon and egg mixture be warm enough to melt the butter? Thank you!

Eileen Gray

Friday 2nd of April 2021

YES, to limoncello! The curd is hot enough to melt the butter and gelatin (unless the butter is frozen or super cold).

Harmony Quinn

Wednesday 10th of March 2021

Eileen, I’m excited to be making this cake for my 40th birthday this weekend. I am vegetarian and so hoping you might be able to direct me on a good substitute for the gelatin in the mousse. I used arrowroot starch in the curd and it turned out great. Can I use that in the mouse as well? Any directions on how much and how specifically to do so? Or would you recommend I use pectin, agar agar, or some other thickener? Or would it be fine without the added thickener since the curd is thickened already? Thank you for your help!

Harmony Quinn

Thursday 11th of March 2021

@Eileen Gray, Okay, so as a follow up...the mouse was NOT thick enough...& the buttercream either too warm or just not strong enough to hold it, lol. The first layer was fine. Even the second layer was okay. By the time I started with the third layer though everything started collapsing and pushing out the sides, then sliding off! Lol! It was a disaster unfortunately. Maybe I should’ve refrigerated it between layers, I don’t know. Really though, I think this illustrates the need for both the curd AND the mousse to be quite thick and strong! I do NOT recommend skipping the gelatin/thickener stages! I wish I could attach pictures of the disaster for illustrative purposes. You’d get a good laugh!

Harmony Quinn

Wednesday 10th of March 2021

@Eileen Gray, Okay great, thank you!

Eileen Gray

Wednesday 10th of March 2021

I don't have a great deal of experience with arrowroot or agar agar. I put gelatin in the mousse so it will hold it's shape when the cake is sliced. The buttercream dam will hold the mousse in place until the cake is cut. I think you might be OK without any thickener. The slices might just be a little soft on the plate. In other words, the slice wouldn't be able to stand up the way it is in the photo. But will work find laying on the plate.

KAREN VENDITTI

Tuesday 22nd of December 2020

my buttercream does not seem to be thickening. Is there anything I can do to help it . How long do I whip it for it to come together?

Eileen Gray

Tuesday 22nd of December 2020

If your meringue is not completely cooled or your butter is too warm, the buttercream can be soft. Try refrigerating it until it begins to firm up. Then rewhip it to bring to back to the correct texture.

Betsy Mains

Friday 11th of September 2020

Hi! I'm so happy to find this site. I love baking and appreciate your expertise here. I made this cake yesterday, and when I took it out of the oven, I almost let it cool upside down, but I didn't because I was worried it would fall out of the pan given the parchment. So, it fell a bit in the middle. but overall the cake still seemed light.

I put it in the fridge so I could assemble today and when I sliced into each layer to divide it, the cake was like a brick. Like zero crumb in some places. I've never seen a cake like that.

Any thoughts as to what might have caused that?

Eileen Gray

Saturday 12th of September 2020

I couldn't say for sure. Perhaps the cake was under baked?

Hanna Paluch

Sunday 23rd of August 2020

Hi, thanks for this awesome recipe! I made it as a surprise for my coworker's birthday last year because she loves lemon and she was blown away. I loved it so much I made it again for my birthday...well a year has passes and I'm making it again for her! This year I told her I was making it so she can get excited (she's been down in spirits lately) . Just wanted to say thank you!!!

Eileen Gray

Sunday 23rd of August 2020

That's wonderful to hear. We can all use a little lift these days.

Skip to Recipe