Raspberry Jam Filling
Quick, easy, and full of flavor, this raspberry jam doubles as a perfect filling or as a base for berry frosting or mousse. Of all my fruit fillings and sauces, this is my favorite.
The story
I’m kind of in a writing rut right now. Like, all I want to do is post a recipe and photos and say, “Make this, it’s yummy.”
Work has been weird. Really great in most ways, really hard in a few ways.
It’s been really cold lately, in a bitter, freeze-your-bones way that only California can manage.
Oh, and I weighed myself last Friday for the first time in over two months. Bad idea. Actually, a good idea that I just didn’t like. It was the push I needed to dedicate myself to being healthier. I’d made some headway in losing the baby weight, but over the holidays my motivation was weak and I kept deviating from what was working. Seriously, girl, get a grip. You know what works to help you lose weight and you just can’t get yourself to stick to it?
Well, I’m hopeful that scale will get me to.
I suppose that’s a good segway to today’s recipe. It’s one of at least eight (yes, eight) raspberry filling/sauce recipes I have.
Years ago, I found out my mom loves raspberry. I remember thinking it was so elegant of her, somehow so sophisticated. What a random conclusion of me to make. But if you think about it, raspberries are elegant. They’re the most fragile berry. They walk the line between tart and sweet with such grace.
Yes, I did just personify raspberries with unnecessary reverence. What can I say? They’re that good.
As a baker, I love including fruit in my desserts whenever I can. For health. Also, for flavor. And a little for calories. I personally like unsweetened fruit fillings, like this one, because they help cut the sweetness of the rest of the dessert. Plus, the taste comes through more without added sweetness.
It’s the kind of recipe that won’t make the scale tell me heart teaming news.
Tips for this dessert
If you want sugar, add it!
I often make this to add to frosting or mousse or to create a berry layer in a sweet cake or spread alongside another frosting. I prefer it unsweetened, to contrast the other flavors and how the berry flavor pop. But if you’re using it in a different way or just prefer a sweeter dessert, add the sugar! As it cooks, you can taste and adjust to your liking.
Layer with frosting to fill drier cakes
I’ve piped this right into cupcakes and used it alone as a cake filling. One thing I’ve found is that it can soak right into drier cakes, and sometimes even into moist cakes after a couple days. Which may be what you want. If not, I recommend spreading a thin layer of frosting before adding the jam to help it stay as a distinctly separate layer. For cupcakes, I recommend making and filling the day they’ll be eaten, since those naturally tend to dry out easily.
Pipe a dam to keep it from spilling out of cakes
Piping frosting is one of my favorite cake hacks. It gives so much more control and keeps crumbs out of your bowl of frosting. Plus, you can use it to pipe dams! Just pipe a ring of frosting along the edge of each layer then spread your jam inside that.
Pro tip: if following the previous tip, spread a layer of frosting, then pipe the dam, then fill with jam.
It will only thicken slightly as it cools
Since this recipe uses cornstarch, you will keep cooking until it thickens to your liking. It will thicken as it cools, but only slightly, so be sure to cook the cornstarch long enough (but don’t go crazy).
Strain seeds before adding cornstarch
I kinda like the seeds in my jam. They give it texture and help it hold its shape. But when I do choose to strain them, I always do so before adding the cornstarch, since it’s thinner and easier to do so.
Don’t burn the raspberries!
I did this recently. It worked out okay, but I kept thinking it would have been better if I hadn’t overcooked the raspberries. Don’t be like me. Be patient and let them break down at medium-low heat.
To pipe filling into cupcakes, use a longer piping tip
My favorite is the Wilton 230. It lets you fill more than just the first 1/2 inch, which is what I usually end up with. You can also cut out some cake or use a voter, but I like having the jam meld with the cake without having to risk it oozing out…and onto my (inevitably) white shirt.
Use as a filling or jam
I love doing a thin layer of frosting and a thin layer of this jam in my chocolate cake (pictured below as cupcakes) or with my vanilla cake/cupcakes (pictured above). It’s also a great alternative to the jam filling in these thumbprint cookies. I’ve stirred leftovers into yogurt and oatmeal and spread it on toast. I also think it would be a great addition to my gooey oopsie bars. Hm. Stay tuned for that one.
Raspberry Jam Filling
- prep time: 5 minutes
- cook time: 20 minutes
- total time: 25 minutes, plus time to cool
Servings: about 2 cups, unless you strain the seeds (enough to fill 24 cupcakes or a 2-3 layer cake)
Ingredients:
- 2 cups raspberries, fresh or frozen
- juice and zest (optional) of 1-2 medium lemons
- 1 tablespoon cornstarch
- 1 tablespoon water (or lemon juice, for a tarter, more lemon-y taste)
- Optional: ¼-½ cup sugar
Instructions:
- Add raspberries, lemon juice, and sugar (if using) to a medium saucepan. (Reserve zest for the end to avoid it developing a bitter taste as it cooks.) Cook over medium-low heat until berries have completely broken down, about 10 minutes, stirring frequently to scrape the edges and also help muddle the berries. You may need to adjust the temperature depending on your stove, but avoid letting the berries boil or “pop” because it burns them and creates a mess.
- Optional: if you do not want the seeds, strain by setting a large fine mesh sieve over a bowl and pushing the berries through with a rubber spatula, essentially squeezing as much juice as you can so as not to lose any flavor or volume.
- Mix cornstarch and water or lemon juice in a small bowl. Whisk or stir into berries until completely dissolved, ensuring there are no clumps. Don’t just pour cornstarch into the pot dry! Clumps will form and you’ll be sad. Probably.
- Continue cooking, stirring frequently, until the mixture thickens to your desired consistency, about 10 minutes (less if you want more of a thick sauce than a filling, but don’t do much more than 10 minutes or it’ll become sticky and eventually taste burnt). It will thicken very slightly as it cools.
- Cool to room temperature or refrigerate if using later. To prevent a film from forming as it cools, stir occasionally or store in an airtight, locking container or sealed jar. Store in the fridge, covered, for up to 2 weeks.
Enjoy!
