Name: Blueberry Cake Filling
Prep time: 5 min
Cook time: 15 min
Total time: 20 min
Yield: 2
Ingredients: 450g (1lb) fresh or frozen blueberries; 50g (1/4 cup) granulated sugar (can be decreased if blueberries are very sweet or increased if tart); 2 Tablespoons cornstarch or arrowroot; 1 Tablespoon lemon juice; 1 teaspoon lemon zest; 1 teaspoon vanilla extract; 1/4 teaspoon salt

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This blueberry cake filling recipe is perfect for cakes, blueberry cinnamon rolls, and blueberry custard pie. It’s thick and flavorful, with a gorgeous color, and can be made with fresh or frozen blueberries.

About this blueberry cake filling

The blueberry flavor in this filling is enhanced with a little lemon juice, sugar, vanilla and a pinch of salt. It’s a versatile filling that can be added to a wide range of treats.

This blueberry sauce is chunky and full of juicy blueberries. It’s similar to a blueberry compote, but this is thickened with cornstarch. Compote usually isn’t. The cornstarch ensures the end result is nice and thick to hold as cake fillings without seeping through the layers.

For another blueberry recipe, check out these blueberry white chocolate muffins!

Ingredients

The ingredient amounts for this homemade blueberry filling are written in the recipe card at the bottom of this post but here is a rundown of what you will need.

Blueberries – They can be fresh or frozen blueberries. Frozen blueberries are usually frozen at their peak ripeness and sweetness, so they will be extra sweet and flavorful.
Sugar (or another sweetener) – Granulated sugar is used in this recipe but you can substitute it for another sweetener if you prefer.
Fresh lemon juice – Lemon juice enhances the flavor of the blueberries.
Vanilla
Salt – Just a pinch to balance the sweetness.
Cornstarch or arrowroot – To thicken the blueberry cake filling.
Water – A little water is used to mix up the cornstarch.

Method

In a medium saucepan, combine cold water and cornstarch. Mix it into a slurry.

blueberries with sugar and lemon zest in a pot.

To this, add the blueberries, sugar, lemon juice, vanilla, and salt.

Place the saucepan over medium-low heat and stir regularly as the mixture begins to warm up.

As the mixture boils, it will thicken, become jelly-like, and lose its cloudy appearance. Let it boil for a full two minutes, stirring continuously, before taking it off the heat. The cornstarch must be cooked through properly, or the filling can lose its thickness.

As the mixture is cooling, cover it with plastic wrap, gently pressing it on the mixture. This stops a skin from forming.

Once cooled to room temperature, store in the fridge in an airtight container until needed.

Storing

This blueberry cake filling can be stored in an airtight container for up to three days in the refrigerator.

Freezing blueberry cake filling

Cake filling made with cornstarch can become spongy or split when defrosted. You can rectify this by reheating the cake filling once it has been defrosted and whisking until it thickens again. If it’s not thickening, add in an extra 1/2 tablespoon of cornstarch mixed with 3/4 Tablespoon water.

You can also substitute the cornstarch in the recipe for arrowroot. This freezes a little better. The same amount of arrowroot powder can be used in place of cornstarch.

Uses for blueberry cake filling

This cake filling is perfect for –

Sandwiching in between layers of vanilla cake to turn it into a blueberry cake recipe, or add it to this lemon curd cake.
Blueberry cupcake filling – Use it as the center of vanilla cupcakes to make filled cupcakes! Use a cupcake corer or small knife to scoop the center of each cupcake out and then fill the middle with blueberry filling. Then top with your favorite frosting
Rolled up in sweet dough to make blueberry cinnamon rolls!
Sandwiched in a blueberry Swiss roll cake.

More cake fillings and compotes