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Easy Blackberry Cake Filling Recipe

3 ingredient blackberry cake filling is easy to make and cooks in less than 20 minutes! Use frozen or fresh blackberries for this simple make-ahead recipe. Use this sweet filling in layer cakes, cupcakes, swirled through cheesecake, baked into sweet rolls, and more!

a slice of lemon cake with black berry frosting and blackberry cake filling on a round white plate. There is a fork of cake and the plate is surrounded by lemon slices and fresh blackberries.

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I first published the original recipe for this blackberry cake filling with the recipe for Gluten Free Lemon Blackberry Cake. But it’s too good and has too many delicious uses only to be used with just one layer cake recipe!

Blackberry cake filling is thicker than a Coulis but not thick and chunky like a compote. To clarify, Coulis is a thin, smooth fruit sauce while a compote is made of stewed fruit that isn’t puréed. 

It’s got a thick and smooth consistency closer to a lemon curd (or other citrus curd) but is made with whole fruit instead of just the juice. It’s also naturally dairy free and egg free, which is what set’s this filling apart from curd fillings. Lemon curd, traditionally, is made with eggs and butter.

So this blackberry filling is the Goldilocks, if you will, which is important if you want it to hold up well between cake layers. It’s the perfect filling for a delicious Lemon Cake and more delectable gluten free treats.


a slice of lemon black berry cake being cut to show the layers of blackberry cake filling

Ingredients and Notes

  • Fresh Lemon Juice – you must use freshly squeezed lemon juice and not bottled lemon juice. Bottled lemon juice is highly concentrated and will make this filling way too tart and acidic.
  • Blackberries – Fresh or Frozen Blackberries – which one should you use? You could use either in this recipe. However, if you use fresh blackberries, you’ll want to make sure they are in season. Out-of-season blackberries can sometimes be fairly flavorless or even tart.
    • Frozen blackberries are picked at their peak ripeness. They’re also easier to buy year-round and are often more economical. 
  • Sugar – this recipe calls for granulated sugar. I have not tested this recipe with alternative sweeteners such as honey, maple syrup, sugar-free alternatives.

*Be sure to read the full recipe card below for exact measurements and step-by-step instructions.

How to Make Blackberry Filling (Visual Step-by-Step Directions)

There are a few simple steps to making a cake filling with berries. I like to strain the seeds out for a smooth filling but if you prefer to keep the seeds for texture and appearance, you can skip that step.

Thickening Fruit Filling 

If you’re having trouble getting the blackberry filling to thicken as much as you’d like, you can make a simple cornstarch slurry. To do this, combine 1 tablespoon cornstarch with 1 tablespoon water and mix it together until the cornstarch is completely dissolved.

Then, when the blackberry filling is bubbling, whisk in the cornstarch slurry. You must whisk continuously because the filling will start to thicken immediately and this will help prevent any lumps from forming.

If your filling still isn’t as thick as you’d like, you can repeat this process with an additional tablespoon of cornstarch and water. You shouldn’t need more than this to get the consistency you’re looking for. Please remember, that the filling will thicken as it cools!

A corn-free option would be to use Tapioca Flour/Starch in place of the cornstarch.

a forkful of lemon cake with blackberry cake filling.

How to Fill a Cake with Blackberry Filling

In order to keep the fruit filling from seeping out the sides of the cake, you’ll have to pipe a buttercream “dam” around the edge of the cake layer. To pipe the dam, I use a Wilton 2A piping tip. If I’m feeling lazy, I just snip the end off a piping bag. You don’t need to use a fancy tip because once the cake is fully frosted you won’t see it and it will seal the blackberry filling inside.

Don’t forget to spread a thin layer of frosting on the cake before piping the dam. This helps prevent the filling from soaking into the cake and making it too soggy.

blackberry cake filling in a layer of cake that has a blackberry buttercream dam piped around it

More Uses for Blackberry Cake Filling

This berry cake filling can be used in different types of recipes. Here are a few of my favorite ways to pair it with desserts:

Tips for Making Cake Filling with Berries

  1. Blackberries are very seedy little gems but that doesn’t mean the filling has to be full of seeds too! It’s important to strain the cooked blackberries through a fine mesh strainer before continuing to cook and thicken. The thinner the blackberry sauce is when you strain it, the more seeds you’ll be able to remove. Of course, if you don’t mind the seeds and like the texture, you can always skip that step.
  2. Be sure to cool the blackberry filling to room temperature and then refrigerate before using. If it’s too warm, it can cause condensation in your baked goods as it cool, which in turn will make them soggy. If you’re pairing it with buttercream, the heat from the filling will melt it, making a big (but tasty!) mess.
close up shot of a 3 layer lemon cake filled with blackberry cake filling and frosted with blackberry buttercream

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close up shot of a 3 layer lemon cake filled with blackberry cake filling and frosted with blackberry buttercream

Blackberry Cake Filling with Fresh or Frozen Blackberries

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3 ingredient blackberry cake filling is easy to make and cooks quickly! Use this sweet filling in layer cakes, cupcakes, swirled through cheesecake, baked into sweet rolls, and more!
Prep Time: 5 minutes
Cook Time: 35 minutes
Total Time: 40 minutes
Servings: 12
Print Rate Pin


  • 2 pounds Frozen Blackberries
  • ¼ cup Fresh Lemon Juice
  • ½ cup Granulated Sugar


  • Add the filling ingredients to a medium-sized saucepan and cover. Heat over medium heat.
    overhead shot of ingredients in a red Le Creuset dutch oven to make Blackberry Cake Filling
  • Allow the berries to defrost and cook for about 10 minutes. Transfer the mixture to a heat proof bowl or quart sized measuring cup and use an immersion blender to carefully blend everything until there are no whole berries remain.
  • Once blended, strain through a fine mesh strainer over the saucepan. This is to remove all the seeds.
    overhead shot of a blended blackberry cake filling ready to be cooked to thicken
  • Continue to cook on medium heat, stirring frequently, around 25-30 minutes. When done, the filling will have halved in quantity and reached a loose, jammy consistency. It will continue to thicken/set as it cools.
    overhead shot of thickend blackberry cake filling in a red Le Creuset dutch oven with a spatula
  • Cool to room temperature then refrigerate until ready to use.


  1. Please read the post for helpful tips on making this cake filling.
  2. Cook time does not include chilling time.
  3. Test the sweetness level after blending and add more sugar if necessary to suit your taste.
  4. To blend the berry compote, you can use an Immersion Blender, regular Blender, Masher, or Nutribullet.
  5. The blackberry filling should be chilled before use.

Nutrition Information

Calories: 66kcal | Carbohydrates: 16g | Protein: 1g | Fat: 0.4g | Saturated Fat: 0.01g | Polyunsaturated Fat: 0.2g | Monounsaturated Fat: 0.04g | Sodium: 1mg | Potassium: 128mg | Fiber: 4g | Sugar: 12g | Vitamin A: 162IU | Vitamin C: 18mg | Calcium: 22mg | Iron: 0.5mg


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

Nutrition Facts are estimated and aren’t always accurate. Please consult a doctor or nutritionist if you have special dietary needs.

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