Making the most delectable raspberry cake filling is easier than you think! Using flavorful frozen raspberries (or fresh raspberries) and just 5 other ingredients, it comes together in less than 15 minutes. Make it in advance so it has time to cool completely before spreading onto your frosted cake layers.
For years, readers have asked if I have a raspberry cake filling recipe published on my website. The answer has always been no, because I’ve never really made a successful batch that tastes great and holds together. But that changed the other week as my kitchen assistant, Beth, and I reduced down endless packages of frozen raspberries over the stove. And so, by popular demand…
When developing this recipe, I started with my recipe for raspberry dessert sauce. I knew I wanted to make it thicker, without straining the seeds, and that it needed to set up nicely so that it wouldn’t ooze out of a cake. It also needed to be a little sticky, so it wouldn’t cause the cake layers to slide around. Oozing, slippery cakes are NOT on the menu today.
The recipes are pretty similar, but this one thickens up into a jam-like consistency thanks to a little more cornstarch and longer cooking time.
Key Ingredients You Need for Raspberry Cake Filling & Why:
- Water & Cornstarch: Cornstarch is the magic thickener for this raspberry filling. You don’t need much, but you must dissolve it in a little water before using. This is called a “slurry”; see strawberry sauce as an example.
- Raspberries: You’ll love the convenience of using frozen berries, which are typically frozen at their peak freshness and sweetness. You need 12 ounces (340g). Fresh raspberries work just as well.
- Sugar: You only need 1/3 cup (67g). The raspberry filling should be a little tart, because you’ll pair it with cake.
- Lemon Juice: The filling needs *something* to balance the berry and sugar, and lemon juice provides that hint of freshness. Do not leave it out or the filling will taste pretty flat.
- Vanilla Extract: Add a little splash of vanilla extract to the filling once it comes off the heat. It tastes and smells incredible!
Just a Few Minutes on the Stove
Stir together all the ingredients—except for the vanilla—in a saucepan set over medium heat. As the mixture heats up and the frozen raspberries thaw, use a silicone spatula to smash the berries. This gets easier as the raspberries soften. By the time it begins to boil, the raspberries should be mostly crushed, so it’s the mixture has an even consistency with no big lumps.
Allow it to boil, still on medium heat, for 5 full minutes, stirring occasionally.
Remove from heat and stir in the vanilla extract. Take a big whiff—it smells amazing!
Let it cool at room temperature for about 15 minutes and then transfer to a heatproof bowl and refrigerate. It will continue to thicken and set up as it chills.
How to Assemble a Cake With Raspberry Filling
I.e., how to prevent the ooze factor.
You’ll have the most success with this raspberry filling in your cake if you partner it with some frosting. My team and I tested a cake with just the raspberry filling in between the cake layers—frosting only on the outside of the cake—and determined it really needs a buttercream base layer to keep the cake stable.
Choose a sturdy frosting, like a vanilla buttercream or Swiss meringue buttercream (more suggestions below). Spread a thin layer on your cake layers, to work as the sturdy base for your raspberry filling.
You Also Need a Buttercream “Dam”
Spoon some into a piping bag fitted with a large round tip, such as Ateco 808. You’ll use this to pipe a “dam” around the edge of the frosted cake layer before spreading the raspberry filling inside its border.
Why am I doing this? The buttercream “dam” keeps the jammy filling in place, so it doesn’t seep out the sides of your cake. You’ll have a bit of an oozy mess otherwise.
After you add the “dam”, spread the raspberry cake filling in the center.
Best Frostings to Pair With Raspberry Filling
Here are some sturdy frostings that you can use as the thin base layer under your raspberry cake filling and piped as a “dam” around it:
Uses for Raspberry Cake Filling
This recipe makes a little more than 1 cup of raspberry filling (about 340g). I find it to be just the right amount for a 3-layer 8-inch or 9-inch cake (with 2 layers of raspberry filling). Use a heaping 1/2 cup between each layer. Or you can use it on a 2-layer 8-inch or 9-inch cake or a 3-layer 6-inch cake, pictured today, and have a little leftover to serve alongside the cake slices (or stir into yogurt, oatmeal, etc). Try it in one of these recipes:
You could also use this cake filling to replace the raspberry preserves in these raspberry streusel bars.
FAQ: Can I Make Raspberry-Filled Cupcakes?
Absolutely, and I hope you try it! Have you ever made my cream-filled chocolate cupcakes before? You’ll fill your cupcakes the same exact way with this raspberry cake filling, and I include those instructions in the filling recipe below. You can use any flavor cupcake, so browse my cupcake recipes to find some inspiration. Pictured here are my vanilla cupcakes.
Raspberry Filling for Cakes
Prep Time: 5 minutes
Cook Time: 10 minutes
Total Time: 15 minutes (plus cooling)
Yield: 1 heaping cup
Category: Dessert
Method: Cooking
Cuisine: American
Description
Using fresh or frozen raspberries and just 5 other ingredients, this raspberry cake filling comes together in less than 15 minutes. Make it in advance so it has time to cool completely before assembling your cake. For best results, I recommend spreading a layer of frosting on your cake layer, piping a frosting dam around the edge, and then spreading the raspberry filling inside the frosting border. See above for a visual.
Instructions
- Whisk the cornstarch and water together until all the cornstarch has dissolved. (I just use a fork to mix—very easy.) Combine cornstarch mixture, raspberries (no need to thaw if using frozen), granulated sugar, and lemon juice in a medium saucepan set over medium heat. Using a silicone spatula, stir the mixture, mashing the raspberries as they begin to thaw and soften.
- Bring to a boil and let it boil for 5 full minutes, stirring occasionally. Remove pan from heat and stir in vanilla extract.
- Allow the raspberry filling to cool at room temperature for 10–15 minutes, then transfer it to a bowl or container and place it in the refrigerator for at least 4 hours. No need to cover it, but if refrigerating for longer than 4 hours, cover tightly. You can refrigerate it for up to 1 week before using. It will continue to thicken up as it chills. Raspberry filling must be completely chilled before using in your cake. If freezing, see Note below for instructions.
- To fill cake: You can use the completely cooled and thickened raspberry filling to fill a 2-layer or 3-layer cake. You’ll have the most success with this raspberry filling if you partner it with some frosting filling; it really needs a buttercream base layer to keep the cake layers stable. Spread a thin layer of buttercream/frosting on your cake layers, to work as the sturdy base for your raspberry filling. Doesn’t need to be much; just a thin layer. You also need a buttercream “dam” around the cake layers to keep the jammy raspberry filling inside the cake layers. Spoon some buttercream into a piping bag fitted with a large round tip, such as Ateco 808. Pipe a border around the cake. Then, spread the raspberry filling inside the buttercream border. An offset spatula is helpful for spreading. Assemble next cake layer on top, and repeat. For a 3-layer 8-inch or 9-inch cake, use a heaping 1/2 cup between each layer. For a 2-layer 8-inch or 9-inch cake, use about 3/4 cup filling and have some leftover. See Note below for other cake sizes.
- To fill cupcakes: With a sharp knife, cut a circle in a cooled cupcake, and remove the center, which will be roughly the shape of a cone. Using a small spoon, fill the middle of the cupcake with as much raspberry filling as you can. (Usually between 1–2 teaspoons.) Slice/tear off the pointed tip of the cone-shaped piece of cupcake, and gently press the round piece back on top of the filling. Repeat with remaining cupcakes. Makes enough filling to fill 2 dozen cupcakes. Or fill 1 dozen, and have some filling leftover.
- Cake or cupcakes filled with raspberry filling and topped with buttercream are typically fine covered at room temperature for 1 day. Cover and store in the refrigerator after that.
Notes
- Freezing Instructions: After the raspberry filling cools completely, freeze in a freezer-friendly container for up to 3–6 months. Thaw on the counter or in the refrigerator before using. It will be very thick.
- What Size Cake: This recipe makes a little more than 1 cup of raspberry filling (about 340g). I find it to be just the right amount for a 3-layer 8-inch or 9-inch cake (with 2 layers of raspberry filling). Use a heaping 1/2 cup between each layer. Or you can use it on a 2-layer 8-inch or 9-inch cake, and fit about 3/4 cup in the center with some leftover. Or try a 3-layer 6-inch cake, pictured today, with about 1/3 cup between each layer.
- Uses for leftover raspberry cake filling: Serve leftover raspberry filling alongside the cake slices or cupcakes. Or add to smoothie, stir into yogurt, cottage cheese, oatmeal, use as a jam on a sandwich, etc.
- I prefer using frozen raspberries: Frozen raspberries are convenient for most, and they usually come in 12-ounce bags which is the exact amount you need in this recipe. It also promises year-round, flavorful raspberry filling. You can definitely use the same amount of fresh raspberries if you have them. The end result is pretty much the same.
- Can I use other berries? I have only tested this with the same amount of fresh or frozen blackberries, and it works wonderfully. No changes to the recipe, just swap the berries. Still working on a strawberry and blueberry version.
Keywords: raspberry cake filling