When I was recipe testing for my Twix cake, I knew I needed a caramel filling that was reminiscent of the candy bar. It had to be extra thick (but not too thick), creamy and spreadable, irresistibly gooey, with just the right vanilla-caramel flavor. So, I researched a lot and tested so many recipes, tweaking things until the caramel was exactly what I was imagining. If you’re looking for a thick caramel filling for cakes and cupcakes, this is it!
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The Recipe Tests
I was originally planning on using my easy salted caramel recipe for my Twix cake. However, after making it I realized, while it was absolutely delicious and does make a great cake filling, it didn’t have the vanilla-based flavor profile I was looking for, nor the thick and gooey consistency. So I played around with a lot of different variables: brown sugar vs. white sugar, different amounts of heavy whipping cream, the temperature the caramel reached in the cooking process, so many combinations that I had to run back to the grocery store multiple times to get more ingredients and try again.
But after testing, tweaking, and lots of waiting for the experiments to come to room temperature so I could really see the consistency, I finally ended up with this recipe. In the end, this is so easy to make, thick and gooey, perfectly sweet, and ideal for filling cakes.
Perfectly Thick Caramel Filling
This caramel filling recipe couldn’t be easier to make. You essentially add all of the ingredients (except for the vanilla) into a large saucepan, melt them together, and cook them until the mixture boils and thickens. It helps to have a thermometer so that you can ensure the caramel reaches 225ºF/107ºC, but it’s not totally necessary so long as you follow the recipe timing in the instructions. It turns out that temperature matters a lot when it comes to the final outcome of the caramel – the higher the temperature reached in the cooking process, the firmer the caramel will set at room temperature.
After all my testing, I think that 225ºF/107ºC makes the perfect spreadable filling consistency for this caramel. It will seem pretty thin right after you make it, but will thicken perfectly as it cools.
This recipe makes a little more than enough to fill a triple 6-inch or 8-inch layer cake, and as a bonus, you can also use it as a drip! At room temperature, it’s the perfect consistency to spread between cake layers, but it can also be heated slightly to make a beautiful (extra thick) caramel drip.
Tips for Caramel Success
This recipe is extremely easy to make, but I do have a few tips that will make it fail proof:
- Use a kitchen scale to measure the ingredients by weight. This will yield the most accurate measurements.
- Stir the ingredients continuously with a silicone spatula throughout the entire recipe. My first attempts were done with a whisk and I wasn’t able to properly scrape the bottom of the bowl, which resulted in brown sugar getting trapped in the edges of the saucepan and burning.
- Use a thermometer to check that the temperature of the caramel reaches 225ºF/107ºC. Any cooler and the caramel won’t be as thick when it sets, and hotter and the caramel will be too thick and chewy when it sets.
- To make sure your caramel filling doesn’t bulge out from between cake layers, follow the soft fillings portion of this filling and stacking tutorial. It will help you add structure to your layer cake and keep all that glorious filling where it belongs.
Cake Recipes Featuring Thick Caramel Filling
I’ve used this thick caramel filling in the following cake recipes, but you can truly pair it with anything that could use some caramel flavor:
Thick Caramel Recipe Video
Here’s a full video tutorial that walks you through the recipe:
If you love recipe videos like this one, be sure to check out my YouTube channel! I’ve got a growing collection of cake recipes, decorating tutorials, and Cake Basics over there. Hit the subscribe button on my page so you never miss a new video.
Thick Caramel Filling
Ingredients
- 1/2 Cup (113g) unsalted butter
- 1 Cup (200g) packed brown sugar light or dark
- 2/3 Cup (210g, 160ml) sweetened condensed milk
- 1/3 Cup (80ml) light corn syrup or golden syrup
- 5 Tbsp (75ml) heavy whipping cream
- 1 tsp salt
- 1 tsp pure vanilla extract
Instructions
- In a large saucepan over medium heat, add the sweetened condensed milk, butter, brown sugar, corn syrup, heavy whipping cream, and salt. Stir with a rubber spatula constantly until the mixture is fully combined and begins to bubble, about 5 minutes.
- Turn the heat to medium-low and continue stirring until the caramel begins to thicken, 6-7 minutes. If you have a candy thermometer, you’ll want to cook this until it reaches 225F/107C. That is the temperature that will thicken the caramel while keeping it nice and soft at room temperature.
- Remove the caramel from the heat and mix in the vanilla extract. Pour into a separate container and let the caramel cool completely to room temperature before using it to fill the cake. You can either leave the container on the counter for about 2 hours or speed the cooling process slightly by placing the container in the refrigerator. It will thicken significantly as it cools.
- Pro Tip: since this filling recipe is so soft, be sure to follow the soft fillings tutorial in this blog post to add structure to your layer cake in the filling and stacking process. This way you'll never have to worry about filling bulging out from between cake layers
Notes
I hope you love this thick caramel filling as much as I do! If you do end up making it, let me know how it went in the comments below + be sure to tag @sugarandsparrowco on Instagram to show me. I love to see what you create!
Amazing! Super thick (or can be thinned out). The best recipe I have tried so far.
Yay, Leanne! I’m so happy you love this recipe as much as I do!
I just wanted to double check what kind of salt you used? I had a salted caramel incident where it called for flaky but I used fine and the caramel was unsalvageable. I’d like to avoid a repeat of that but I couldn’t find if you specified what salt you used
Hi Zari! I didn’t specify but I always use kosher salt.
Hi, just wondering if the whipping cream has to be heavy. Thanks!☺️
Hi Katrina! Whipping cream typically has slightly lower fat percentage than heavy whipping cream (usually has 36% fat) which might make the caramel softer when room temperature. I haven’t tried it with whipping cream though, so if the fat percentage isn’t much lower it might not make much of a difference. Hope that helps!
Have you frozen this filling? Some caramel doesn’t freeze well, it goes grainy. I want to freeze my cake and ice it later but I want it to stay smooth!
Hi Brittany! I haven’t tried freezing this caramel recipe before, so I’m not sure how it would go. Feel free to experiment and report back if so!
Silly question, but if I was to make this into a salted caramel filling, would I just add more salt? And if so, how much would you recommend? Thanks so much! 🙂
Hi Sam! For more of a salted caramel flavor I would add 1/2 tsp more salt. Taste it at the end (carefully, before cooling) and add more salt if needed. Enjoy!
Amazing thank you so much!
This is my absolute favorite recipe for caramel. I used it as a filling for my carrot cake at my mom’s wedding! I would love to turn these into caramel chews for Christmas. Do you know if the recipe will work for chews if cooked to a higher temperature? I know standard for those are 245ish degrees, just not sure if the creaminess of this will work if cooked higher…
That’s wonderful, Kim! I’m so happy this recipe has become your go-to! I have never intentionally made chews with this recipe but I have cooked it past 225ºF and it definitely firmed into a firmer/chewier consistency at room temperature. I’d say try it!
The answer is yes! I doubled the recipe, cooked it to 245, then poured it into a half sheet pan to cool. Used a pizza cutter to slice them into bars and individually wrapped them. They’re perfect! So much better than the ones in the gold wrapper. Not to mention they’re gorgeously speckled with homemade vanilla paste. I wish there was a way to share a picture!
Hooray, Kim! I’m so happy you reported back. Now I want to try them!
Tasted like heaven, came together really easily tooo… the first recipe where i didnt burn the sugar lol
Thank u so much for the wonderful recipe
Yay, Poorvaja! I’m so happy to hear it was a success!
Lovely recipe. Can I double it? I want to make a 9 inch 3 layer chocolate cake with the thick caramel filling and a Caramel buttercream frosting.
Hi Victoria! You should be able to double this recipe, just make sure you make it in a large pot and expect slightly longer cooking times. Enjoy!
I filled some sugar cookies with this caramel. Should these be refrigerated or can they be left out?
Hi Erika! That sounds amazing! They should be totally fine at room temperature for a few days. Enjoy!
Could I use this as a sandwich cookies filling or would I need to heat the caramel more?
Hi Susie! This should work great as a sandwich cookie filling! Just be sure to cool it first because it thickens as it cools.
Can you freeze it?
Hi Stella! I haven’t tried freezing this before, but from a little research it looks like its possible to freeze caramel and thaw at room temperature when you’re ready to use it.
If I cook it for a shorter time will it be a thinner consistency?
Hi Belle! I haven’t tried cooking it for a shorter time since I was going for a thick caramel with this recipe but I have a hunch that it would yield a thinner caramel if you cook it just until it begins to bubble (in step 1) or for just a few minutes after that. I also have this salted caramel recipe that isn’t as thick: https://sugarandsparrow.com/salted-caramel-recipe/
Thi was my first time making caramel! Recipe easy to follow and tastes delicious! I have chosen to try and add some to my brownie mix and then bake! Hope it comes out as delicious as it sounds! (Beginner home baker here)
Yum, Cheryl! That sounds delicious! So happy you loved this recipe 🙂