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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.
Happiest Friday everyone. We’re celebrating sweet cake and I am so excited. I’ve been holding onto this for a couple of weeks. I’ve 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, we’re switching to berries, cake, and frosting and it’s going to be pretty darn great.
The Inspiration
I would love to say that the inspiration for this cake was Asher’s 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, I’m sure I’ll 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 – 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 it’s simplified down into a yummy sheet cake.
The jam is quick, but delicious…fresh blackberries, sweet honey, dried lavender, and a squeeze of lemon. Boil everything together until the jam thickens up and turns jammy.
This isn’t your traditional jam however, it will not be jelly-like. It’s 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 jam…
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 olè 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 that’s it. Simple. Simple.
Now pour the batter into a rectangle baker.
Now the fun part – 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. Don’t 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, that’s what you’ll need. Beat that all together and you’ll have one of my favorite cake frostings.
No one ever knows there’s white chocolate in the frosting. But it’s 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 don’t 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, don’t forget to tag me on Instagram! Looking through the photos of recipes you all have made is my favorite!
Swirled Blackberry Lavender Sheet Cake
Servings: 12
Calories Per Serving: 781 kcal
Nutritional information is only an estimate. The accuracy of the nutritional information for any recipe on this site is not guaranteed.
Ingredients
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
Instructions
- 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. 2. Preheat oven to 350° F.  Line a 9×13 inch baking dish with parchment paper.3. In a large bowl, beat 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 combined 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. 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!
This looks amazing! Wondering if I could freeze the cake? Better to do with or without the icing?
Thanks!
Hey Melissa,
Thanks so much! Yes, you could totally freeze this cake, I would do so without the icing:) Please let me know if you have any other questions! xT
How long can we store the cake? If I were to make it Thursday, will it be good to eat by Saturday? Thank you 🙂
Hi Melissa,
I would store in an airtight container in the fridge and it should be just fine. I hope you love this recipe! xT
Was curious if this recipe could be used for cupcakes?
Hey Amy,
Sure, that should work nicely for you! Let me know if you give this recipe a try, I hope you love it! xT
Is there a different oil that can be substituted for the coconut oil? If so which would be best?
Hey Valerie,
You could use any other neutral oil that you enjoy in place of the coconut oil. Let me know if you give this cake a try, I hope you love it! xT
I use Avocado oil and it turns out fine every time!
would substituting the sour cream with vegan coconut yoghurt work, do you think? i made this cake before and it turned out phenomenally. this time i’m using strawberry instead of blackberry jam.
Hey there,
Totally, I think that would work nicely for you!! Thanks so much for making this recipe:) xT
Can the jam be made a day ahead of time and refrigerated?
Hey Erin,
Of course! You could make the jam up to 1 week in advance:) I hope you love this recipe! xT
Could I do strawberries in place of the blacklberries?
Hi Whitney,
Sure, that would work nicely for you! Let me know if you give this recipe a try, I hope you love it! xT
YUM! I brought this cake to a party today, and it was devoured.
The cake was light n fluffy.
The jam swirls were tart, sweet & floral all at the same time.
The hint of lavender was perfect.
The white chocolate in the buttercream was smooth & rich.
What a delectable dessert!
I wonder if toasted macadamia nuts sprinkled on top would work?😋
Hey Dale,
Wonderful!! I’m so glad to hear that this recipe turned out well for you, thanks so much for making it:) Sure, I bet the macadamias would be great! Have a great weekend! xT
Followed the instructions to a T and it came our a soupy mess. It looked fine when I pulled it out of the oven- golden along the edges, and just formed center, not wiggly…I let it cool all the way, then put on the frosting. I cut into it to serve and was SO let down when it turned into a lava cake of sorts. Such a let down.
Hi Molly,
Thanks for trying this cake and sharing your feedback, so very sorry to hear you had some issues. It sounds like it wasn’t baked long enough….did you try sticking a knife or toothpick in the middle to double check? What kind of baking dish did you use, was it glass by chance? xx
Hi! My son made this cake and it was delicious. However, it was a little in the dry side. What could have gone wrong?
Thanks!
Hi Megan,
Thanks for sharing this feedback! It’s hard to say without knowing more info…Is it possible it was over baked? What kind of baking pan did he use? Was there anything he adjusted in the recipe? Let me know and I’m happy to help troubleshoot! xx
I noticed that milk is listed in the ingredient list but not within the instructions – possibly they forgot the milk… I added the milk with the wet ingredients assuming that’s what was intended?
The milk is listed in step 3:)