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Keeping this sweet, simple, and delicious with this Swirled Blackberry Lavender Sheet Cake. Light and fluffy vanilla cake swirled with homemade blackberry lavender jam. Then generously frosted a sweet vanilla bean white chocolate buttercream. This cake is nothing short of delicious. Every bite is layered with fresh berries, hints of lavender, and sweet vanilla cake. The perfect berry-filled cake for any and all occasions.
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Happiest Friday everyone. Weโre celebrating sweet cake and I am so excited. Iโve been holding onto this for a couple of weeks. Iโve wanted to share this since the day I first made it, but peach recipes took top priority last week. Which is totally fine, because of course, they too are so delicious.
This week, however, weโre switching to berries, cake, and frosting and itโs going to be pretty darn great.
The Inspiration
I would love to say that the inspiration for this cake was Asherโs upcoming 13th birthday. BUT, that girl wants nothing to do with a non-chocolate cake. So, as much as I would love to be remaking this for her birthday on the 30th, Iโm sure Iโll be making the standard chocolate cake.
The real inspiration was super simple, I wanted to bake a cake. I wanted it to be light and happy and pretty. I want to have fun photographing it, and I wanted it to be my most delicious vanilla cake yet.
Excitedly reporting that this cake checks all of the above boxes. Sometimes you just have to make what you really, really want to make.
The details โ starting with the jam
If you guys have followed along for a while you may remember my blackberry layer cake. This cake is very, very similar flavor-wise, but itโs simplified down into a yummy sheet cake.
The jam is quick, but deliciousโฆfresh blackberries, sweet honey, dried lavender, and a squeeze of lemon. Boil everything together until the jam thickens up and turns jammy.
This isnโt your traditional jam however, it will not be jelly-like. Itโs more of a sweet, thick blackberry sauce. Make the jam first so that it has plenty of time to cool off.
Pairing lavender with blackberries is a favorite combo of mine. The flora hints from the lavender compliment the sweetness of the blackberries, and when mixed together in a jamโฆ
It is so good!
Onto the vanilla cake
When it comes to vanilla cake I like to keep my cake recipes pretty straightforward. And I always go heavy on the vanilla. I love to use real vanilla beans for added flavor, but of course, good olรจ vanilla extract works great too.
Mix the coconut oil with sour cream, eggs, sugar, and that vanilla. Then just add flour, baking powder, baking soda, and a nice pinch of salt. Stream in a little milk and thatโs it. Simple. Simple.
Now pour the batter into a rectangle baker.
Now the fun part โ swirl in the jam
Take the blackberry jam from earlier and dollop spoonfuls over the cake batter, then use a knife to gently swirl the jam around. Donโt over mix, the idea is to have pretty swirls of jam throughout the cake.
If you over-swirl, the cake will still be great, but more of a purple color.
While the cake bakes, make the frosting
Butter, sugar, lots of vanilla, and melted white chocolate, thatโs what youโll need. Beat that all together and youโll have one of my favorite cake frostings.
No one ever knows thereโs white chocolate in the frosting. But itโs what makes this buttercream extra special and leaves everyone wanting more.
Finish this up
Once the cake has cooled, spread over a thin layer of the blackberry jam, then dollop over that frosting. The frosting is sweet and creamy, and everything together is DELICIOUS.
Once again, take the jam and add small spoonfuls to the top of the baked cake. Then use a knife to gently swirl the jam into the frosting. It turns the prettiest shade of purple and I love it.
Yes, what I love most about this sheet cake is how just pretty it turns out with minimal effort. The beauty of a sheet cake is that you donโt have to cut or layer anything. Just bake, frost, and enjoy!
This is the perfect cake to make on a rainy summer afternoon. Especially if you have one too many boxes of sweet berries!
Looking for other sweet cake recipes? Here are some favorites:
Swirled Berry Ice Cream Butter Cake
Swirled Blueberry Lemon Thyme Cake
Coffee and Fudge Ice Cream Cak
Lastly, if you make this Swirled Blackberry Lavender Sheet Cake, be sure to leave a comment and/or give this recipe a rating! Above all, I love to hear from you guys and always do my best to respond to each and every comment. And of course, if you do make this recipe, donโt forget to tag me on Instagram! Looking through the photos of recipes you all have made is my favorite!
Swirled Blackberry Lavender Sheet Cake
Ingredientsย
Blackberry Lavender Jam
- 6 cups fresh or frozen blackberries
- 1/2 cup honey
- 1 tablespoon lemon juice
- 1-2 tablespoons dried lavender
Blackberry Cake
- 1 cup melted coconut oil
- 1/2 cup sour cream
- 3 large eggs
- 1 1/2 cups granulated sugar
- 1 tablespoon vanilla extract
- 1 cup milk
- 3 cups all purpose flour
- 1/2 teaspoon baking soda
- 1 1/2 teaspoons baking powder
- 1 teaspoon kosher salt
Vanilla White Chocolate Frosting
- 2 sticks (16 tablespoons) salted butter, at room temperature
- 1 1/2 cups powdered sugar
- 6 ounces white chocolate, melted and cooled
- 1 teaspoon vanilla extract
Instructionsย
- 1. To make the jam. Add the blackberries, honey, lemon juice, and lavender to a medium-size pot set over high heat. Bring the mixture to a boil, once boiling use a potato masher or fork to break down and mash the berries. Continue to cook for 5-8 minutes or until the jam has reduced and thickened by 1/3. Remove from the heat and let cool. This should thicken as it cools.ย 2. Preheat oven to 350ยฐ F. ย Line a 9ร13 inch baking dish with parchment paper.3. In a large bowl, beatย together the coconut oil, sour cream, eggs, sugar, and vanilla. Add the flour, baking soda, baking powder, and salt. Mix until just combined, then slowly beat in the milk until fully combinedย 4. Pour the batter into the prepared pan. Take about 1/2 cup to 3/4 cup of the jam and dollop it by the tablespoon over the cake. Use a knife to lightly swirl the jam around, don't over mix it. 5. Bake 30-35 minutes, until the top is just set and no longer wiggly in the center. Remove and let cool completely before frosting. 6. To make the frosting.ย In a large bowl, beat together the butter and powdered sugar until light and fluffy. Add the melted white chocolate and vanilla, beat until combined.7. Spread a thin layer of jam over the cake, then frost the cake all over. Add small spoonfuls of the jam to the frosting and gently swirl the jam into the frosting. Slice, eat and enjoy!
Nutrition
Nutritional information is only an estimate. The accuracy of the nutritional information for any recipe on this site is not guaranteed.
Did you make this recipe? Please rate & comment below.
This was absolutely delicious and I successfully made it using gluten free flour and some extra baking powder!! I have a question about the dried lavender though. The pieces of lavender stayed in the jam and they were a bit unpleasant to bite into. How would I make the jam without adding the lavender directly into it? Can I steep the lavender in some water and then add that? But would the jam be too watery if I did that? Thanks!
Hey Adriana,
Thank you so much for giving this recipe a try and sharing your thoughts, so happy it worked for you!
You could put the lavender into a cheesecloth to steep in the jam and then remove it. I hope this helps!
Could I use cake flour instead of all purpose?
Hi Desire,
Sure, that should work nicely for you. I hope you love this recipe!
How much jam should I make, if I want to use it all up, without any left over ?
Hi Donna,
So sorry, I am not sure the measurements for that. Please let me know if I can help in any other way!
One of the comments stated she had a ton of jam left over from this recipe. Do I use all the jam this recipe calls for or does this recipe make way more jam then you need ?
Hi Donna,
You really shouldn’t have much jam leftover:) Please let me know if I can help in any other way!
I have tons of blackberry jam left over. Can I freeze it?
Hi Christine,
Sure, that would work nicely for you!
Please let me know if you have any other questions!
Itโs strawberry season where I live. Can I use strawberries instead?
Hey there,
Sure! Here are some other strawberry recipes you might enjoy:
https://www.halfbakedharvest.com/strawberry-poptart-sheet-cake/
https://www.halfbakedharvest.com/strawberry-chamomile-naked-cake/
https://www.halfbakedharvest.com/strawberry-shortcake-sheet-cake/
Please let me know if you have any other questions!
What is the best substitute for the coconut oil? This not something I use (yet). I
Hey Cate,
Another neutral oil or melted butter will work nicely for you.
I hope you love this cake, please let me know if you give it a try!
Can I use cupcake pan instead of 9×13 sheet pan? Would be the same measurements?
Hey Carol,
Sure, that should work nicely for you! I would just reduce your bake time:) I hope you love this recipe!
This is an amazing cake! The sweet tart flavor of the jam really makes this cake delicious and special!
Thank you SO much Suzanne! So so happy to hear you enjoyed this cake! It’s perfect for summer! ๐ xT
This is amazing! Should it be stored in the fridge or on the counter?
Hey Kirstin,
Love to hear this recipe turned out well for you!! I would keep this in the fridge, especially if your kitchen is on the warmer side with the summer heat! Have a great weekend!
Iโm so excited to try this recipe! But where can you find dried lavender?
Thanks so much, Sarah!! I like to order mine from Gourmet Sweet Botanicals. Please let me know if you have any other questions! xx
Whatโs the best way to store this if you make the day before? Better to wait on frosting it until day of?
Hey Nicole,
Yes, if you can wait on the frosting that would be best. I like to keep this covered in an airtight container in the fridge. Please let me know if you have any other questions!
Did it taste much better if you make it the day of. Hoping to make the cake tonight and ice it tomorrow before a party
Can you also use a spring form pan for it to be circular instead?
Hi Cassie,
You would probably need to adjust the baking time. I haven’t tested this, so let me know if you give it a try! xT
I am obsessed with this cake. I had to sub in dairy free ingredients due to a dairy allergy and it worked perfectly!
Thanks so much, Cheryl! So glad this recipe was enjoyed, I appreciate you making it! Happy Sunday!๐ผ๐ฐ
Are these high-altitude friendly instructions or should I adjust somehow for baking?
Hey Emily,
You can follow the recipe as written, you shouldn’t have any issues:) I hope you love this recipe! xT