This blueberry filled cake with lemon buttercream has to be the perfect Spring cake! This lemon cake is is filled with homemade blueberry jam and covered in a creamy frosting that’s made with fresh lemon juice and zest. It takes just 25 minutes to prepare this lemon blueberry cake.
I absolutely love a layer cake for celebrations or gatherings. Last year I created a vanilla cake with a blueberry Swiss meringue buttercream and filled with a blueberry jam. This cake though is frosted with a fluffy buttercream with a lemon flavor and has a homemade blueberry compote filling. I also sprinkle over some fresh blueberries on top of the compote to get that extra blueberry taste!
Tell me about this recipe!
- The cake layers are flavored with vanilla extract and lemons. The cake has a moist crumb thanks to yogurt that is used in the cake!
- We make a sweet blueberry filling by boiling down fresh blueberries with a bit of sugar and water. Juicy berries are then sprinkled on top while assembling the cake.
- The cake is frosted with an American buttercream, flavored with lemon zest and lemon juice.
- I decorated this cake with candied flowers which I think is so beautiful for Spring.
All Purpose Flour: I’m using all purpose flour in this cake
Eggs: as this cake is a white cake, it is mainly made with egg whites with 1 egg yolk to give a softer and more moist crumb
Vanilla Extract: try to use a high quality vanilla extract, it makes a huge difference!
Whole Milk: I use whole full fat milk, I don’t recommend using low fat milk.
Yogurt: I’m using yogurt but you could also use sour cream if you don’t have any yogurt.
Unsalted Butter: I always use European style butter in my cakes. It has a higher butterfat content which will give you a much richer (and tastier!) cake.
Fresh Blueberries: I have only tested this recipe with fresh blueberries and not frozen blueberries
Cornstarch: also known as corn flour in the UK, this will be used to thicken up the blueberry preserves that we make.
How to make this recipe
Step 1: In the bowl of a stand mixer fitted with the paddle attachment, mix all of the dry ingredients on slow speed until well blended. Add in your butter and mix on low speed until the mixture looks like damp sand.
Step 2: In a medium bowl or jug, whisk together the milk, yogurt, vanilla extract, lemon juice and lemon zest.
Step 3: Add your egg whites, one at a time, to your dry ingredients. Then add your whole egg. Beat well after each addition on medium speed and make sure to scrape the sides of the bowl.
Step 4: Slowly pour in one third of your wet ingredients into the cake batter and mix on low speed. Repeat twice more, be careful as it may spill out of your bowl! Note, you could also use a hand mixer for these steps but be sure to use a large bowl. Divide batter evenly into 2 8-inch round cake pans, greased and lined with parchment paper. Bake at 350 degrees for 25-30 minutes. If you stick a toothpick in the center of the cake it should come out clean. Let the cakes cool briefly before removing them from their pans and letting them cool completely on a wire rack.
Step 5: Time to make your blueberry filling! In a medium saucepan over medium-low heat, stir your blueberries and ⅛ cup of water together. Cook for 15 minutes until the fruit begins to break down. In a separate bowl, whisk together your cornstarch and sugar. Add this sugar mixture to the blueberries and turn the heat to medium. Cook for 3 minutes, until it begins to boil, stirring constantly.
Step 6: Pour the blueberries into a bowl and let it cool completely. It can be stored in the fridge in an airtight container for up to 3 days.
Step 7: In a stand mixer fitted with the paddle attachment, beat the butter and powdered sugar together on low speed.
Step 8: Increase the speed to medium-high and beat until it becomes very thick. Turn off the mixer and add your lemon juice, lemon zest, vanilla extract and salt. Beat on medium speed. Turn the mixer to low and add your heavy cream. Beat until the frosting is thick and spreadable. Time to assemble! Place one cooled cake layer down and spread a small amount of lemon frosting over it. Then use an offset spatula to spread the blueberry filling over, though leave about half an inch border all the way around (so it doesn’t seep out). Sprinkle over fresh berries. Place the second layer on top. Use a small offset spatula to cover the sides of the cake with a thin layer of frosting to make a crumb coat. Then cover the cake with the rest of the frosting. I used a small spoon to create swoops and swirls.
Recipe Tips and Tricks
- I highly recommend using a weighing scale and measuring out your ingredients the metric way. It makes a huge difference to your baking and is the most accurate way to bake! If you aren’t using a weighing scale, make sure you are measuring your flour properly with your cups. Check out this link here on how to do that using the fluff, sprinkle and scrape technique.
- I make sure that all of my ingredients are at room temperature before I start the recipe, so pull out all of the ingredients an hour or two ahead of time.
- Allow your cakes to cool completely before you assemble the cake with the frosting. Otherwise your frosting will melt and slide right off!
- You can make the cake layers ahead of time. Bake and then once cooled completely wrap each layer in plastic wrap. Refrigerate for up to 2 days or freeze for up to 2 months. Bring it to room temperature before frosting. You can also make the blueberry filling up to 3 days ahead of time.
How to make candied flowers
It is so simple to make these beautiful flowers! Find flowers that are safe to have on your cake. I used pansies, voilets and daisies. Wash them carefully, then in a small bowl whisk an egg white with a few drops of vodka or water. Use a small paintbrush to paint the petals with a thin layer of the egg white mixture, making sure to also paint the back of the flower. Sprinkle over granulated sugar. Place the sugared flowers on parchment paper and let them dry overnight. Carefully place them on top of the cake. I then peeled them off when the cake was done (we weren’t eating the flowers) and placed them in an airtight container, as they can keep for a few weeks.
Frequently Asked Questions
Make sure your cornstarch is still in date! Then if your blueberry filling isn’t thickening up in the pan, let it cool down to room temperature and place in the fridge. It should thicken up more in the fridge after a few hours.
Yes, wrap up the cake tightly and keep in the fridge for up to 5 days.
Try these layer cakes next!
Blueberry Filled Cake
- 2 8-inch cake pans
- 2 ½ cups all purpose flour
- 12 tablespoons unsalted butter room temperature
- 1 ⅔ cup sugar
- 2 teaspoons baking powder
- ½ teaspoon baking soda
- 1 ½ teaspoons kosher salt
- 4 egg whites room temperature
- 1 egg room temperature
- 2 teaspoons vanilla extract
- 1 cup whole milk room temperature
- ½ cup full fat yogurt room temperature
- 2 teaspoons lemon juice
- 1 teaspoon lemon zest
- 1 cup fresh blueberries
- ⅛ cup water
- 1 tablespoon cornstarch
- ¼ cup sugar
- 4 sticks unsalted butter room temperature
- 6 cups confectioners' sugar
- ½ teaspoon kosher salt
- 2 tablespoons lemon juice
- 1 teaspoon lemon zest
- 1 teaspoon vanilla extract
- ¼ cup heavy cream double cream in the UK
- Preheat your oven to 350°F/175°C. Grease and line two 8-inch cake pans
- In the bowl of a stand mixer with the paddle attachment, mix all of the dry ingredients on slow speed until blended. Add in your butter and mix on low until it looks like damp sand
- Add your egg whites one at a time, and then your whole egg. Beat well after each addition, making sure you scrape the sides and bottom of the bowl.
- In a small jug, whisk together the vanilla extract, yogurt, lemon juice, lemon zest and milk.
- Slowly pour in one-third of the milk mixture into the mixing bowl. With the speed on low, mix together. Be careful as it may spill! Pour in the rest of the milk in two more additions, mixing slowly after each addition.
- Beat for 2 minutes. Your batter will be liquidy
- Pour the batter into your two pans. Bake for 25-30 minutes. A toothpick inserted into the cake will come out clean. Remove from the oven and let cool for 15 minutes. Take the cake out of the tin and let it cool completely.
- In a medium saucepan over medium-low heat, stir together the berries and water. Cook for 15 minutes. The fruit will start to break down.
- Whisk together sugar and cornstarch in a small bowl. Add sugar mixture to the juice and turn heat to medium, cook until it comes to a boil – about 3 minutes
- Pour into a bowl and let come to room temp. Can be stored for 3 days in the fridge in an airtight container.
- In a stand mixer fitted with the paddle attachment, beat the butter and powdered sugar together on low speed
- Increase the speed to medium-high and beat until it becomes thick
- Add the lemon juice, lemon zest and salt and beat on medium-high
- Turn the mixer to low, and pour in the cream until it becomes creamy and spreadable
- Place one cake layer down. Scoop out some of your lemon buttercream and use a small offset spatula to spread a layer of frosting down. If you wish you could make a barrier to stop the filling from spreading out. Do this by placing some of the frosting in a piping bag and pipe around the border of the cake.
- Scoop out your chilled blueberry filling and use a spoon or offset spatula to smooth out the filling on top of the lemon buttercream. Sprinkle over a small handful of extra fresh bllueberries if you wish! If you didn't make a barrier, then just make sure to leave a half inch border all around the cake so it doesn't seep out.
- Place the second layer on top and press down gently. Evenly cover the sides and top of the cake with the rest of the frosting.
- Decorate the top of the cake with sprinkles, blueberries or candied flowers.