This seedless raspberry cake filling is perfectly tart and comes together with simple ingredients and techniques. You can use fresh or frozen raspberries to make it, and the recipe yields a beautifully thick raspberry filling that’s perfect for cakes and cupcakes. It pairs wonderfully with so many cake flavors and adds a bright, jammy burst in every bite!
Side note: if you prefer to keep the seeds in the filling, use this raspberry cake filling recipeinstead!
Seedless Raspberry Cake Filling Ingredients
The raspberry filling uses 5 simple ingredients and comes together so easily:
- Fresh or Frozen Raspberries. If you have fresh raspberries on-hand, great. Frozen raspberries are more readily available year-round, and they work perfectly for this recipe.
- Cornstarch + Water. Mixing equal amounts of cornstarch and water together creates a slurry, aka a thickening agent for this filling.
- Granulated Sugar. This sweetens the raspberries just enough so that you still have the perfect amount of tartness.
- Lemon. Using a little lemon juice and zest compliments the raspberry flavor beautifully.
How to Make Seedless Raspberry Cake Filling
While the raspberry cake filling comes together in about 20 minutes, you will need an additional 4 hours of cooling time for the filling to thicken. You can store it for up to a week, so it’s a great element to make ahead of time!
Step 1: Add almost everything in a medium saucepan and simmer. Add the raspberries, sugar, lemon zest, and lemon juice into a medium saucepan set over medium heat. Stir to combine the ingredients and continue stirring occasionally as the raspberries soften, mashing them up as you go. Once the raspberry mixture starts to boil, you’ll reduce the heat and continue simmering it for about 15 minutes, stirring frequently.
Step 2: Strain out the seeds. Place a fine mesh sieve over a medium bowl and pour the filling into it. Press with a rubber spatula to strain out the seeds until you have just about ¼ Cup of seedy pulp remaining on the sieve.
Step 3: Add the cornstarch slurry. In a separate small bowl, combine the cornstarch and water to make a slurry. Add the strained filling back into the saucepan and mix the cornstarch slurry in.
Step 4: Cook to thicken. Bring the filling mixture back to a boil over medium heat, stirring frequently, and cook for a few more minutes until the filling is thick, glossy, and coats the back of the spatula.
Step 5: Cool. Pour the raspberry filling into an airtight container and cool in the refrigerator for at least 4 hours. This will thicken the filling into a jello-like state, but after stirring the filling back up it will make it the perfect consistency for filling cakes, cupcakes, and more!
How to Fill a Cake with Raspberry Cake Filling
This seedless raspberry cake filling is thick, but not thick enough to support a layer cake on its own. To make it more stable, you’ll need to build a buttercream dam around the edge of each cake layer before filling in the center with the raspberry filling. Buttercream is thick enough to support the weight of cake layers in the filling and stacking process. Whipped ganache also works great as a dam if that’s what you’re using to frost the cake.
To build the dam, fill a piping bag with buttercream or whipped ganache and snip off about ½ inch opening on the end. Place the first cake layer on your turntable and pipe a ring around the edge about ¼ inch inward from the edge of the layer. Then, fill in the center with raspberry filling and smooth it down until it’s level with the top of the buttercream dam or just slightly below.
Add the next cake layer on top and repeat the process of filling and stacking until you have one cake layer left. Place that final cake layer upside down on top of the filling so that the bottom of the layer becomes the top of the cake.
This process of filling and stacking the cake with a buttercream dam makes the cake with a soft filling like this much more stable, helping to prevent the filling from oozing out or bulging.
Cake Recipes to Pair With Raspberry Filling
I originally made this seedless raspberry cake filling for my vanilla raspberry layer cake, but it pairs amazingly well with a variety of cake flavors! One batch of this filling will be enough to fill any of the recipes below. You’ll want to use it in place of whatever filling is listed in the cake recipe (if there is one). Here are some of my favorite suggestions:
- Bakery-Style White Cake
- Lemon Raspberry Layer Cake
- One-Bowl Chocolate Cake
- Pistachio Cake
- Coconut Layer Cake
You can also use this recipe to fill up to 15 cupcakes (here are some cupcake recipes to try)! It doubles well in case you need more.
I hope you love this seedless raspberry filling as much as I do! Let me know if you make it in the comments below (and what you paired it with!) and don’t forget to tag @sugarandsparrowco on Instagram to show me a photo. I love to see what you create!
Seedless Raspberry Cake Filling
Equipment
Ingredients
- 2 1/2 Cups (10oz, 315g) fresh or frozen raspberries
- 1/2 Cup (100g) granulated sugar
- 1 Tbsp lemon juice
- 1 tsp lemon zest
- 1 1/2 Tbsp (12g) cornstarch
- 1 1/2 Tbsp (22ml) water
Instructions
- In a medium saucepan, add the raspberries, granulated sugar, lemon juice, and lemon zest. Set the saucepan over medium heat and stir with a silicone spatula to combine. Cook until the mixture begins to boil, mashing down the raspberries as they soften.
- Once the mixture starts to boil, lower the heat and simmer for 10-15 minutes while you continue stirring occasionally. Then, remove from heat and use a fine mesh sieve to strain out the seeds over a medium bowl. Use the silicone spatula to press the raspberry mixture into the sieve, scraping the other side of the sieve often to capture the strained raspberry mixture. After straining, you’ll be left with about 1/4 Cup of seedy pulp.
- In a small separate bowl, combine the cornstarch and water until uniform. Return the strained raspberry filling to the saucepan (wipe it free of any remaining seeds if needed) and add the cornstarch/water mixture. Set the saucepan over medium heat and bring the mixture back to a boil, stirring constantly. Once it's boiling, reduce the heat to a simmer and let it cook for 1-3 minutes, until the filling has thickened slightly, is no longer cloudy, and coats the back of the spatula.
- Pour the raspberry filling into an airtight container and refrigerate for at least 4 hours and up to 1 week. The longer you refrigerate, the thicker and more flavorful it will be. It will be jello-like once set but after stirring it will become a thick, jammy consistency.
- When the raspberry filling has cooled and thickened, you're ready to use it as a cake or cupcake filling! If you're using it to fill a cake, be sure to pipe a buttercream dam around the edge of your cake layer before filling in the center with this raspberry filling. This way it won't squish out from between your cake layers. This blog post has more details on the filling process.
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