Lemon Blueberry Shortbread Mousse Cake

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This Lemon Blueberry Shortbread Mousse Cake is to die for and perfect for spring and summer! It’s incredibly light and almost completely no bake! With layers of lemon and blueberry mousse, white chocolate ganache and a Walkers Shortbread crust, the only thing that requires a few minutes in the oven is the crust!

This post is sponsored by Walkers Shortbread, but all opinions are my own.

Lemon Blueberry Mousse Cake on a white cake stand

Lemon Blueberry Mousse Cake slice on blue plate

I don’t know about where you are, but here in Atlanta it’s finally getting warm and everything is starting to bloom. We have a hill behind our house that is mostly covered in bushes and we know it’s spring when this particular kind of bush blooms. They always bloom first and for only a couple days. It’s really sad it lasts so little because they’re pink and pretty. 🙂 But they do signal that the warm weather is here! Yay!

I love the bright, vibrant flowers and all the fresh fruit. Everything just comes alive! I feel like this cake is the perfect way to kick off spring. It’s fruity, bright and cheerful. Plus, it’s seriously delicious.

There’s a layer of lemon and blueberry mousse on top. Both are simple to make and oh so light. They sit atop a layer of white chocolate ganache that rests on top of a wonderful, buttery shortbread crust.

The layer of ganache and shortbread crust is one of the best parts of this cake! Seriously, if you’ve never tried Walkers Shortbread you really must. They are SO buttery and delicious, they basically melt in your mouth. I can’t stop eating them. And unlike a lot of things, they contain no artificial flavorings, colorings or additives. The ingredients on the box are literally four things – flour, butter, sugar and salt. They’re the jam. They even have several gluten free flavors.

Lemon Blueberry Mousse Cake overhead view
Lemon Blueberry Mousse Cake on a cake stand with a slice on a plate in front

The crust is a mixture of the shortbread crumbs, a little sugar and little butter. It’s less butter than I normally add to crusts because there’s already so much buttery-ness in the cookies. The crust is baked and then topped with white chocolate ganache with a bit of lemon zest in it. Amazing.

Layered on top of that is the lemon and blueberry mousse. The lemon mousse is made with lemon curd and some gelatin and whipped cream. The blueberry mousse uses blueberry puree that is strained, thickened with gelatin, then added to whipped cream. Both mousse layers are incredibly light in texture. The flavors are also light, but just enough.

Everything comes together beautifully. Such refreshing flavors complimented with the buttery crust for a light crunch. Pure heaven and your new favorite dessert. 😉

Lemon Blueberry Mousse Cake on a cake stand
Lemon Blueberry Mousse Cake slice on a blue plate

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Slice of Lemon Blueberry Mousse cake on a blue plate

Lemon Blueberry Shortbread Mousse Cake

  • Yield: 12-14 Slices
  • Category: Dessert
  • Method: Oven
  • Cuisine: American


A light cake with layers of lemon and blueberry mousse, white chocolate ganache and a buttery shortbread crust.



  • 1 3/4 cups Walkers shortbread crumbs (two 5.3 oz packages, about 15 cookies)
  • 2 tbsp sugar
  • 2 tbsp (28g) butter, melted


  • 8 ounces (227g) white chocolate chips
  • 3 tbsp (42g) unsalted butter
  • 3 1/2 tbsp (53ml) heavy whipping cream
  • 2 tsp lemon zest


  • 1/4 cup (60ml) fresh lemon juice (12 lemons)
  • 2 tsp finely grated lemon zest
  • 1/3 cup (69g) sugar
  • 4 egg yolks
  • 3 tbsp (42g) unsalted butter


  • 2 tsp powdered gelatin
  • 2 tbsp (30ml) cold water
  • 1 3/4 cups (420ml) heavy whipping cream
  • 3/4 cup (86g) powdered sugar
  • 3/4 cup (180ml) lemon curd


  • 1 1/2 cups (8 oz) blueberries
  • .25 oz package unflavored powdered gelatin
  • 1 3/4 cups (420ml) heavy whipping cream
  • 3/4 cup (86g) powdered sugar


1. Preheat oven to 350 degrees. I would suggest lining the sides of a 9 inch springform pan with parchment paper that goes about one inch above the sides of the pan. The mousse will come all the way to the top and just a touch above. The parchment paper ensure that the pan sides will be tall enough. It’ll also make it easier to remove the cake from the pan at the end.
2. To make the crust, combine the crust ingredients in a medium sized bowl, then press into the bottom of the springform pan.
3. Bake the crust for 10 minutes, then remove from oven and set aside.
4. To make the white chocolate ganache layer, place the white chocolate chips in a medium sized bowl. Heat the butter, heavy whipped cream and lemon zest in a glass measuring cup. The butter should melt and then the whole mixture should come to a boil. Once boiling, pour the heavy cream mixture over the white chocolate chips, then cover for about 5 minutes.
5. Whisk the white chocolate mixture until smooth. If it doesn’t completely melt, microwave in 10 second increments, whisking in between, until smooth.
6. Spread white chocolate ganache evenly over the crust, then refrigerate until firm.
7. To make the lemon curd, combine all ingredients in a double boiler (or in a metal bowl over a pot of simmering water, like I did). Heat while stirring constantly with a whisk until mixture reaches 160 degrees. Refrigerate until thick and cool.
8. Once lemon curd is cooled and firm, finish the lemon mousse. Sprinkle the powdered gelatin over the cold water in a small bowl. Allow to sit for about 5 minutes, then heat for about 5-10 seconds, whisking until warm and smooth. Set aside to cool to room temperature.
9. In another mixer bowl, whip heavy whipping cream on high until it begins to thicken. Add powdered sugar and continue to whip on high until stiff peaks form, while slowly pouring in the cooled gelatin.
10. Carefully fold the lemon curd into the whipped cream, then spread the lemon mousse evenly over the white chocolate ganache.
11. To make the blueberry mousse, puree blueberries then press through a strainer to remove pulp.
12. Sprinkle the powdered gelatin over the blueberry puree, trying to make sure the powder is all touching the puree. Set aside for about 5 minutes to bloom and firm up.
13. Once gelatin is firm, heat in the microwave for 5-10 seconds, then whisk until melted and smooth. Set aside to cool to room temperature.
14. While gelatin mixture cools, make the whipped cream. Whip heavy whipping cream on high until it begins to thicken. Add powdered sugar and continue to whip on high until stiff peaks form.
15. Once the gelatin is room temperature, fold it into the whipped cream until well combined.
16. Spread the blueberry mousse in an even layer over the lemon mousse layer, then place in the refrigerator.
17. Refrigerate cake until firm, 5-6 hours, then remove from springform pan and place on a serving plate. Top cake with blueberries and lemon slices/zest.
18. Refrigerate until ready to serve.


  • Serving Size: 1 Slice
  • Calories: 540
  • Sugar: 33.1 g
  • Sodium: 123.7 mg
  • Fat: 39.7 g
  • Carbohydrates: 42.8 g
  • Protein: 5.5 g
  • Cholesterol: 146.8 mg

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Recipe inspired by the Triple Chocolate Mousse Cake in this cookbook, Bonjour, Ya’ll.

Lemon Blueberry Mousse Cake - This cake is almost entirely no bake and perfect for spring and summer! A layer of blueberry and lemon mousse on top of white chocolate ganache and a Walkers Shortbread crust!

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  1. Shirley DeGeorge

    Your recipes are SOOOOOO Awesome!! Photography also exceptional! As a very senior lady that still loves to bake (& mostly from scratch, like you)I’m wondering if there is a video for the Lemon-Blueberry Mousse cake? Need a bit of a refresher for the gelatin use. Thanks for sharing all your tips as well!

    1. Lindsay

      Thank you! I’m so glad you enjoy the recipes! Unfortunately, there is not a video for this recipe. I’m sorry.

  2. Maryan

    Hi, I have a 10 in springform pan and I am scared that I won’t make enough. I was wondering if you can help me how to covert the recipe.

  3. Sherry Santiago

    I have been a baker for over 30 years and when I made this recipe for Father’s Day my mother stated it was the best cake I have ever made and has requested I make it again for a luncheon we are having tomorrow. Thank you for this easy to follow delicious recipe.

  4. Michelle

    Brand new baker here and this recipe has literally convinced my roommates that I am a baking god!! Super clear and easy to follow steps even for a newbie like me. Over the moon with how this turned out!! Totally agree with Debbie about the gelatin, that tricky smelly guy haha Really excited to try some of your other recipes 🙂

  5. Amanda

    Hi, this cake looks delicious but I have a question about the amount of blueberries-it says 1 and 1/2 cups is equal to 8oz but it’s actually equal to 12oz as one cup is 8oz.

    1. Lindsay

      So one cup is equal to 8oz when you’re talking about liquids and volume. It’s a little different for solids and weight. All things weigh differently because some are just heavier than others. In this case, 1 1/2 cups of blueberries is about 8 oz by weight, not volume. Does that help?

  6. Debbie

    Lindsay, OMG!! I made this mousse cake and the flavor combinations were amazing. However this was my first mousse cake and working with gelatin so I had some issues. I think  my biggest issue definitely was with the gelatin. Please do a video tutorial on knowledge with mousse and gelatin. I watched a couple and neither gave me much insight. The videos really only cover how to turn it in to a solid and how to liquify. For those of us that has never dealt with building a mousse cake are shocked when it goes wrong because we fill as thought we followed the recipe to a T.  After blooming and heating my gelatin at 10 seconds in the microwave and stirring to make sure all granules were well liquified I left it to cool while preparing next step which was whipping my cream. Fir the lemon curd when I went to put the gelatin in with the curd it started out smooth and liquid but before I could spoon out the rest, it had solidified. I honest just reached in and grabbed the solid gelatin and  discarded., praying I had enough in the lemon mousse to set. When I went to put my  blueberry gelatin and folded it in carefully, all looked well. I did freeze the mousse cake because I wanted to do a mirror glaze. I smoothed and put it in the freezer. My cake looked just as pictured  when I pulled it out to  complete the mirror glaze.  When we cut the cake I used the tips you provided with a warm knife. It cut perfect cake pieces.   My thoughts of excitement to put a piece of this mousse cake in my mouth grew times a million . When I had my third bite  not  so great, I had a couple small pieces of gelatin in my blueberry mousse ? hmm What did I do wrong? ???What do I do when my gelatin is solidified when also  putting in to the cream… …. do I stop, reheat and  try again or do I discard and start over? Please HELP!! I would hate the thoughts of never being able to master this amazing cake. Please do a video for this and demonstrate to beginners what could go wrong and how to master it. I would so appreciate it. Btw, I love every recipe I have made of yours . Each one has been absolutely awesome!! Even with my hard bits of gelatin, I gave  this 5 stars!  😋Thank you  so much!! 

    1. Lindsay

      Thank you for the feedback Debbie! Gelatin can definitely be a little tricky. I’d love to do more of a tutorial for working on it and will! Thanks!

  7. Rosa

    Greetings! I’m so not savvy in the kitchen. Basically, if I don’t see a video, I know I’ll mess up the steps. Just curious: can I skip the lemon curd making process (which sounds the most daunting to me) and buy it already made and then mix it to make the lemon mousse layer? Thanks!! 

    1. Lindsay

      I promise lemon curd isn’t as hard as it seems. 🙂 I would suggest using the curd listed in the recipe, just because store bought is often a different thickness and you want it to be thick enough to stand up in the mousse. Feel free to check out my recent post on Lemon Curd for some tips.

  8. Dan M

    Hello.  We are making this but came up against confusion on step 4.  It does not say how to bring the butter etc to a boil?  Are we making it in a double boiler or  the microwave… or what? A glass measuring cup in a pot of boiling water?

  9. Sandra

    Hello! i have a question about the lemon curd – I don’t have a thermometer so is there another way of knowing when the curd is ready at 160 degrees?

    1. Lindsay

      The description is generally “thick enough to coat the back of a spoon”, but that is kind of vague, which is why I like to use the temperature.

    1. Lindsay

      The blueberry-gelatin mixture is heated until smooth, then allowed to cool a bit. It’s solid before heat, but afterwards, should be smoother.

  10. Karen Lu

    Thanks Lindsay. Your recipe is gorgeous. I made it today for my hubby birthday. Everyone love it. Thanks for all the replies to help me out too. 

  11. Karen Lu

    The lemon layer abit collapsed. Too moist can’t stand up nicely. So that’s why harder to hold the blueberries layer. The bluberries layer looks ok. Just taste a bit too fluffy. 

  12. Karen Lu

    I have tried the recipe. The cake removed from the springform pan and then cut to eat, but my cake so moist and not stand nicely. I am not sure which part I made mistake. After I removed from the pan, do I need to refrigerate more before able to serve for eating?

    1. Lindsay

      Once it’s been refrigerated for the 5-6 hours, it should be fine. Did you use the full amount of powdered sugar listed for the mousse layers? I know sometimes people reduce them to reduce the amount of sugar, but they also help stabilize the mousse.

      1. Karen Lu

        Hi I didn’t reduce the amount of sugar. I used icing sugar, is that right?  Will that be possible that I over whisk the heavy cream to make it too fluffy?

      2. Lindsay

        That is correct. Over whipping shouldn’t be an issue either as long as it’s nice and thick. Do you know which layer was too thin? Or was it overall?

  13. Andrea

    I saw someone asked about making the cake ahead and freezing, but do you think the individual parts could be pre-made – the mousse for example – and kept in the fridge and then assembled a day or two later?

    1. Lindsay

      It might be ok. I’d be a little hesitant with mousse though, just because once it sets in the fridge (like in the bowl you’re storing it in) it might not re-set again quite as well after stirring everything back up again.

  14. Debbie

    This cake looks absolutely AMAZING – the only thing that puzzles me is in the blackberry mousse – is .25oz enough?? That’s only a quarter of an ounce for 420ml cream, 8 oz blueberries and 86g powdered sugar. How can this be enough to set that?
    Many thanks.

  15. Anna

    All of your cakes that I have made have been amazing and I can’t wait to try this one. But my question is on step seven which says to make the lemon curd but should this be the lemon mousse? Sorry to be dense but I just want to make sure I’m not going to mess up the steps. I plan to make this for Easter dinner.

    1. Lindsay

      I’m so glad you’ve enjoyed the cakes you’ve made! The lemon curd is part of the lemon mousse, but the ingredients are listed separately for clarity purposes. The lemon curd is added to the mousse in later steps. I hope that helps!

  16. Joanne

    Could this cake be frozen? I’d love to make it for my son’s birthday but don’t have time close to the actual day. 

    1. Lindsay

      I’ve never tried it, but I think it’d be ok if well covered. I’d suggest thawing it in the fridge when you’re ready.

  17. Erica Harris

    This is a nice summery cake.

    I probably won’t make it again not because it wasn’t delicious but because it’s so much work. If I were to make it again however, I would half the ganache because it was way to thick and overpoweringly sweet as a result. Once I scraped half of it off and put it with the mousse components its was really lovely. I would also skip the sugar for the crust.

    I found the ganache steps were unnecessary and when the butter was clearly never going to boil, I just made the with a basic double boiler method.

    I cannot wait to try more cakes from this site!

  18. Jane

    Hi, I need a recipe which has no baking element (I do not have a working oven at the moment). Is there a way I can create a shortbread base which requires no baking? 

    1. Lindsay

      You could still make this recipe as is, just don’t bake the crust. It’ll still work fine, though the crust may have a few more crumbs than normal. You could add a bit more butter to help hold it together.

  19. jesus ramiro quispe onofre


    1. Lindsay

      Hmm, I thought it was nationwide. I usually find it on the cookie isle in my grocery store. I’ve even seen it in Home Goods! 🙂

  20. Julia@HappyFoods

    Now this is what I call a perfect cake! And the pictures – they are absolutely beautiful! I remember eating Walkers shortbread for the first time – simply delicious! 

  21. Lynne

    Lindsay, this shortbread mousse cake is stunning.  I really want to try it 🙂  Thanks so much for sharing it.  Hope your day is wonderful 🙂

  22. Mir

    I’m excited about everything blooming. Just give me some warm mild temps and I’m happy! And the flowers smell so good.
    This cake is amazing. Like, incredible. The only person you can one-up at this point is yourself, since your cakes are beyond!

About Lindsay

I'm a wife and a mom to twin boys and a baby girl! And I've got a serious sweets addiction! Bring on the treats!

Scripture I’m Loving

“Come to me, all you who are weary and burdened, and I will give you rest. Take my yoke upon you and learn from me, for I am gentle and humble in heart, and you will find rest for your souls.” Matthew 11:28-29