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This easy, fruity strawberry cake filling takes less than 20 minutes to make. Use it to fill a multi-layer vanilla, chocolate or strawberry cake topped with strawberry or vanilla frosting.
Making your own fillings, whether they are for cakes or for cupcakes - such as this raspberry cupcake filling, are easy to do and worth the effort.
- This filling is made with frozen strawberries which means that you can make this recipe any time of the year. It is also much less expensive to use frozen strawberries, rather than fresh ones.
- This strawberry filling can be used in a variety of ways other than to fill a cake, such as in cupcakes, to fill tarts, or served with fresh yogurt.
- It is easy to make in less than 20 minutes, so you can make it while your cake layers are baking in the oven.
Ingredients & Substitutions
- Strawberries: This recipe uses frozen strawberries since they are cheaper and easy to buy any time of the year. However, you can use fresh strawberries if you want. For fresh strawberries, reduce the cornstarch by about half since fresh strawberries tend not to have as much juice as frozen ones.
- Lemon Juice: A little bit of lemon juice brightens the strawberry flavor. Use fresh lemon juice for the best taste.
- Sugar: A small amount of sugar adds a bit of sweetness. If needed, you can substitute this with brown sugar.
- Cornstarch & Water: Cornstarch is mixed with water to create a slurry that will thicken up the strawberry filling to the right consistency. You can substitute this with arrowroot powder if needed.
- A saucepan to make the filling in.
- A whisk to whisk the ingredients together.
- A mason jar to store any leftover filling in.
Step 1: Heat the strawberries, sugar and lemon juice together on a saucepan over medium heat. Bring the mixture to a light simmer for a couple minutes to allow it to thicken up. Then, reduce the heat to low.
Step 2: In a separate bowl, mix the water and cornstarch together until well combined. While on low heat, mix the cornstarch and water mixture into the strawberry filling. Stir until evenly distributed, and the filling has thickened up. Remove the filling from the stovetop.
Step 3: To fill the cake, allow the filling to fully cool to room temperature. Then, pipe a layer of buttercream frosting around the edge of the cake layer to act as a dam. Add the strawberry filling to the center, and place the next cake layer on top.
How to Assemble the Cake
The steps for assembling a cake with strawberry filling are the same no matter what recipe or flavor you choose for the cake base and frosting.
First, cool the cake layers completely. You can chill them in the fridge or even in the freezer. This firms them up, making it easier to frost.
Make sure to pipe a thick line of frosting around the edge of the cake layer. Use a frosting that holds its shape so it can hold in the filling.
Then, fill the center of the cake layer with the chilled strawberry filling. It is important that the layer of frosting is just as high, or higher, than the layer of strawberry filling so it doesn’t ooze out.
Gently add the next layer on top, and repeat if making a third tier. Once the layers are added, chill the cake for 30 minutes and then frost the top and sides with the rest of your icing.
Make Ahead & Storage
To store leftover filling, first let the filling fully cool to room temperature. Then, store the filling in an airtight container in the fridge for up to a week.
Once stored in the fridge, the filling will thicken up slightly and you may need to microwave it for 5 to 10 seconds to loosen it up before using it.
Once you have used the filling to assemble a cake, the cake must be stored in the fridge.
This strawberry filling does not freeze well. Any filling that has cornstarch in it can’t be frozen. This is because the cornstarch comes apart and ruins the consistency when frozen. If you plan to freeze the filling, use arrowroot instead of cornstarch.
- Adjust the thickness. If the filling is too thick, add a small amount of water (about 1 teaspoon at a time) to thin it out. Do this while heating the filling over low heat. If the filling is too thin, add an extra 1 to 3 teaspoons of the 1:1 cornstarch to water mixture.
- Don’t add the cornstarch directly to the filling. Always make sure to mix the cornstarch in water before adding it to the filling. Otherwise, the cornstarch will leave clumps in the filling.
- Warm the filling in the microwave if needed. After storing this filling in the fridge, it will thicken up. Microwave it for 5 to 10 seconds, just enough to loosen it up, but not enough to actually heat it.
- Let the filling and cake layers cool first. Let the strawberry filling and your baked cake layers fully cool to room temperature before assembling the cake.
- Don’t overcook the filling. This can cause the cornstarch to become lumpy. If this happens, add a bit more water and whisk.
- Blend for a smooth filling. This filling has some chunks of strawberries. For a smooth filling, blend or pulse it in a blender afer it has cooled down.
Other Uses for Strawberry Filling
This recipe is mainly meant to be used as a filling for a multi-layer cake. However, there are a number of other ways you can use this recipe:
- Cupcake Filling: Once your baked cupcakes have fully cooled, remove a round circle about an inch wide and an inch deep. Add a couple tablespoons of the strawberry filling. Replace the top of the cupcake and frost.
- Tart Filling: Add the filling to a prepared pie tart and bake until golden.
- Ice Cream: For a sweet topping, add a small amount of filling on top of a fresh scoop of vanilla or strawberry flavored ice cream.
- Pancakes & French Toast: For a decadent breakfast, serve this filling on top of pancakes or french toast, along with whipped cream and maple syrup.
- Yogurt: Adding a scoop on top of vanilla or plain yogurt with granola mixed in makes for a delicious breakfast.
- Puff Pastry: Bake a few scoops of this filling into a puff pastry.
- Cheesecake: If you love cheesecake, try adding a dollop on top of a vanilla cheesecake.
Yes. However, fresh strawberries don’t have as much water as frozen ones. You may need to add a bit of extra water to the filling to get the right consistency.
Yes. However, you may need to adjust the amount of cornstarch and water you add depending on how much liquid the berries you are using have.
This makes about ¾ cup to 1 cup of filling.