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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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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!

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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.

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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!

Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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

Prep Time 30 minutes
Cook Time 30 minutes
Total Time 1 hour
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

Blackberry Cake

Vanilla White Chocolate Frosting

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!
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Swirled Blackberry Lavender Sheet Cake | halfbakedharvest.com

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Comments

  1. This may seem like a ridiculous question, but when/how do you remove this cake from the pan? Before or after you frost it? Thanks!

    1. Hi Laura,
      Using the parchment paper, you should be able to easily lift the cake from the pan and then frost it. You can refer to the photos above:) Please let me know if you have any other questions! xTieghan

  2. 5 stars
    I am 28 years old. In 28 years, I have NEVER seen my dad eat dessert. I made this, and not only did he eat it, he asked for a second piece! I’ve made this for two different family parties this summer, and it’s always a hit. So delicious and bursting with flavor!

    1. Hey Liz,
      LOL wow, that is pretty impressive! I love to hear that it was a winner, thanks for making it! Have the best Thursday! ?xTieghan

    1. Hey Helen,
      Happy Wednesday! I am thrilled to hear that this recipe was a hit, thanks a bunch for giving it a try! xx

  3. I am making this cake today! I have looked at it for months but just haven’t had the time. I’m so excited! This cake is so pretty and sounds absolutely delicious! I made the jam the other day. It turned out perfectly! Can’t wait to get it made!

    1. Hi! I’m planning on making this recipe for my sons birthday, my question is can I make it into 3 8 in pan and stack them up With this frosting? Thank you ?

  4. This looks delicious! Could these be made into cupcakes instead? What would change re: cooking time and temperature? Thank you!

    1. Hi Andrea,
      Sure, cupcakes would work, I would keep the overnight temp the same just start checking for doneness at 25 minutes. I hope you love the recipe:)

  5. 5 stars
    Incredible. I made half the jam as some recommended and it was a great amount. Cake and frosting are both perfection.

    1. Hey Caroline,
      Awesome!! Thanks so much for making this recipe, I am so glad to hear that it was enjoyed. Have the best weekend! ?xxT

  6. 5 stars
    OMG. I have been wanting to make this cake for ages but had never done it… I finally made it tonight for a big family dinner and it was a HUGE hit! SO delicious – So moist and flavourful! Would 100% make this again – thanks so much Tieghan! 🙂

    Tamara

    1. Btw – I substituted gluten tree self raising flour, and made a coconut cream frosting instead as I’m not good with dairy. It was absolutely delish!

    2. Hi Tamara,
      Happy Friday! Thanks so much for sharing your feedback and trying this recipe out! Love to hear that it was enjoyed:) xxTieghan

  7. 5 stars
    I have made this 3 times now (for work and for friends) and everyone LOVES it. I didn’t have lavender when I made it to bring to work, so I need to make again so I can try with the lavender. I highly suggest trying it if you are tempted! It’s easy and so pretty! Thanks for sharing this, it’s so delicious!

    1. Hi Kara,
      Fantastic!! Thanks a lot for trying this recipe out and sharing your feedback, I love to hear that it was enjoyed! xxT

  8. 5 stars
    In case anyone is wondering, this recipe can be easily halved and baked in an 8×8 pan. I did it today and it baked beautifully in about 28 minutes. I used one whole egg and one egg yolk. I strained my jam, which made it a little on the thin side, but it didn’t seem to affect the recipe. I would definitely make this again!

    1. Hey Jackie,
      Love to hear that this recipe was a hit, thanks for making it and sharing your feedback! Thanks for sharing what worked well for you. ??xTieghan

  9. This recipe is incredible. I’ve made it twice now to rave reviews both times. Thank you!!

    Do you store the leftover cake in the fridge?

    I also have extra jam. How long will it keep for?

    1. Hey Stephanie,
      Happy Sunday! Thanks so much for making this recipe and sharing your feedback!! Love to hear that it was a winner:) Yes, I like to keep it in the fridge and the jam is good up to 2 weeks in the fridge. xxT

  10. 5 stars
    I can’t wait to try this, if I made it the day before s party would it hold up well?
    Thanks!

    1. Hey Jacqueline,
      Totally, I would wait to add the frosting until the day of if you can:) Let me know if you give the recipe a try, I hope you love it! xTieghan

  11. I love these flavours together! I was apprehensive to make the white chocolate frosting, as I usually find it too sweet, but it offsets the tartness of the berries perfectly and tastes delicious ! The cake itself is amazing too: moist, tasty and not overly complicated.
    Thanks for the great recipe Tieghan 🙂

    1. Hey Nicole,
      Awesome!! I am thrilled to hear that this recipe was enjoyed, thanks a bunch for giving it a try! xx

  12. Hi, Tieghan! I LOVE all of your stuff and this cake especially! I am even going to make it for my upcoming wedding this July! I am doing a practice sesh for my SIL and was wondering, if I make it a tiered cake with three or so layers, what do you recommend I set the timer for? Thanks so much!

  13. 5 stars
    My original review got lost or deleted so here is my condensed review. This cake is wonderful and any leftover jam is a delightful addition to yogurt or cocktails, it’s not a difficult bake and the end result is a home run.

    1. Hey Roxanne,
      Thanks so much for giving this recipe a go and sharing your feedback!! I love to hear that it was a winner:) xTieghan

  14. 5 stars
    Stepped out of my comfort zone and attempted this lavender cake. Didn’t look as pretty as yours but it tasted so good. My cake was very dense though and I’m not sure if that was right??? Maybe I didn’t something wrong. Overall a great cake and I’ll for sure make again!

    1. Hey Kimberly,
      Wonderful!! Thank you so much for trying this recipe and sharing your feedback! I am so glad it was enjoyed. So sorry to hear it was dense. Was there anything you may have adjusted? Was your baking soda and powder fresh? Have a great week! ?xxT

      1. It was not. I was also thinking it might have had something to do with the baking soda/powder. I will definitely try again and make sure the soda and powder are fresh…see if that makes a difference! Otherwise it was all to the T of the recipe 🙂 Thank you so much for your suggestion!