Blackberry Lime Cake – tender cake infused with lime zest, frosted with blackberry buttercream, topped with fresh blackberries and edible flowers.
Spring is officially here. While our local weather has been up, down and everywhere in between, my heart is ready for birds chirping, green buds of new growth on the trees and blooms of color. Mother Nature might be slow to cooperate, but this is the time of year to embrace color, in all of its pastel glory. From Easter and Mother’s Day to baby and bridal showers, there’s ample opportunity to dive straight into the lush florals and gorgeous hues that springtime has to offer. And today’s Blackberry Lime Cake does not disappoint.
This is cake is a celebration of everything spring. Shades of violet sing as sweetened blackberries meet up with subtle notes of lime, created only with nature’s best. Not only are we decorating with gorgeous edible flowers but we’re tinting the frosting with the pigments naturally found in fresh blackberries. The result is a subtle lavender hue that looks like it came from a bottle but really came from the earth’s bounty.
Fresh blackberries are somewhat underutilized in cake baking, probably because of their large size and high water content. If you take a pack of fresh blackberries and toss them into a silky buttercream frosting, you’ll end up with a sad soupy mess. Add fresh berries to a cake batter and they’ll sink straight to the bottom. So we’re taking fresh berries and reducing them down, I’m talking way down, past the jam or jelly stage to really concentrate the flavor. The result is almost like a paste once it sets up. When mixed into our frosting, it clumps ever so slightly, giving a beautiful speckle to the finished cake, which closely resembles bits of broken berry.
The end result is not overly tart, nor overly sweet, just delicate blackberry that’s mild and easy to eat. If you really want to amp up the blackberry flavor, slice some berries in half and add them between your cake layers, to get that fresh berry punch. The choice to go big or stay mild is up to you. Either way, this one is definitely worth a go.
Blackberry Lime Cake
Blackberry Lime Cake – tender cake infused with lime zest, frosted with blackberry buttercream, topped with fresh blackberries and edible flowers.
- Yield: One 8" Round Cake (3 layers)
- Category: Dessert
- Cuisine: Cake
Ingredients
For the Blackberry Lime Cake:
- 3 cups all-purpose flour, spooned and leveled
- 1 tablespoon baking powder
- ½ teaspoon baking soda
- ½ teaspoon salt
- 2 tablespoons organic lime zest
- ¾ cup whole milk
- ¼ cup lime juice
- 8 ounces unsalted butter, room temperature
- 2 cups granulated sugar
- 4 eggs, room temperature
- 2 teaspoons vanilla extract
For the Blackberry Reduction:
- 12 ounces fresh blackberries
- 1 tablespoon granulated sugar
- 1 tablespoon lime juice
For the Blackberry Buttercream:
- 6 egg whites
- 1 ½ cups granulated sugar
- 1 ½ cups unsalted butter, softened
- 1 teaspoon vanilla extract
- 3 tablespoons blackberry reduction
For the Assembly:
- 12 ounces fresh blackberries
- edible flowers (micro pepper, alyssum and micro mint) washed and dried
Instructions
Make the Blackberry Lime Cake:
- Preheat oven to 350F. Butter and lightly flour three 8″ round pans. Line with parchment paper circles.
- Whisk together flour, baking powder, baking soda and salt. Zest limes and whisk into flour. Set aside.
- In a small bowl, combine milk and lime juice. Stir to combine and set aside for milk to curdle. This is similar to making homemade buttermilk.
- In the bowl of a stand mixer, beat butter and sugar on medium-high using the paddle attachment. Beat until pale and fluffy, about 3 minutes.
- With the mixer on low, add eggs one at a time. Mix well after each egg.
- Add vanilla extract and mix to combine.
- Add the flour mixture in three batches, alternating with the milk, beginning and ending with the flour mixture. Do not over mix. Stop the mixer and scrape down the bowl and the mixer blade.
- Divide batter evenly between the three 8″ round pans.
- Bake for 25-27 minutes, or until toothpick inserted into center comes out clean.
- Let cool in pans for 5 to 10 minutes, then remove to wire rack to finish cooling.
Make the Blackberry Reduction:
- Combine blackberries, sugar and lime juice in a pan over medium heat.
- Cook 10 to 15 minutes until the juices are bubbly and the berries are soft enough to smash with the back of a spoon.
- Press the mixture through a fine mesh strainer into a clean bowl to remove the seeds. Use the back of your wooden spoon to really press as much pulp through as you can. Scrape the underside of the strainer to get all of the accumulated blackberry pulp. Discard seeds and return strained puree back to the pan.
- Cook on medium, stirring with a wooden spoon, until reduced to only a few tablespoons, about 10 minutes.
- Pour into a small bowl and cover with plastic wrap, pushing the plastic down to touch the blackberry reduction so that a skin does not form. Allow to cool.
Make the Blackberry Buttercream:
- Place egg whites and sugar into the bowl of a stand mixer, whisk until combined.
- Place bowl over a pan of simmering water to create a double-boiler. Whisking constantly, heat the egg mixture until it registers 160 degrees on a candy thermometer. Carefully transfer the bowl onto the stand mixer.
- Using the whisk attachment, beat the egg white mixture on high speed for 8 to 10 minutes until the bowl is no longer warm to the touch and the meringue is fluffy, glossy and holds a stiff peak.
- Switch to the paddle attachment. With the mixer on low, slowly add cubed butter and mix until incorporated.
- Add vanilla extract and whip on medium-high until silky and smooth, about 3 to 5 minutes.
- Add blackberry reduction and whip again until incorporated. The buttercream may look like it’s broken at some point. Keep mixing until it is completely smooth.
Assemble the Cake:
- Place one layer of cake onto serving plate or cake stand and top with about one cup of blackberry frosting.
- Repeat with second cake layer, more frosting and then last layer of cake. Crumb coat and frost cake with remaining frosting.
- Decorate with additional blackberries and edible flowers. Start by laying out blackberries in a crescent shape, spacing them close together but not touching. Tuck in small sprigs of the micro mint here and there, but not everywhere. Next, add the alyssum, using only the top blooming section of each sprig. Add a few extra berries for height if needed. Fill remaining small holes with the micro pepper blooms.
- Reserve extra berries and blooms to adorn individual slices when serving, if desired.
Notes
- Be careful not to pack flour into the measuring cups. Too much flour can result is a heavy and overly dense cake. Spoon flour into the measuring cup and then level off the excess.
- When finished mixing the cake batter, be sure to scrape down the mixer blade to grab all the lime zest that has accumulated. Fold back into the cake batter before diving into pans.
- You may bake this as two full-sized 8″ round cake layers. Alternatively, I baked it as three intentionally shorter 8″ round layers – this saves time and effort because the shorter layers do not need to be torted. The resulting layers are approximately 1.25 inches tall. If only using two pans, be sure to only fill them 2/3 of the way full to prevent overflowing.
- If at any point the buttercream appears curdled, just keep mixing. If the buttercream appears soupy, try placing it in the refrigerator for about 10 to 15 minutes then mixing again.
- To amp up the fresh blackberry flavor, make a double batch of blackberry reduction and spread a thin coating between the cake layers. Or slice fresh berries in half and add them between the cake layers.
- Add flowers just before serving as they will wilt over time, especially when refrigerated.
- Store in refrigerator. Serve at room temperature.
Can I make it in 6″ pan. And I do not have 3 of them so I can I make one at a time. I know it’s time consuming but do not want to buy 2 extra ones and I do not really have time to do so. Thank you
I’m planning on making this today. But I was curious, can I make into cupcakes instead ?!
Thank you
Yes, this recipe should make around 30 cupcakes, give or take a few. Bake around 17-19 minutes or until a toothpick inserted in center comes out clean. Enjoy!
Hi Carrie, can I make this recipe into cupcakes easily? Thank you
Yes, this recipe should make around 30 cupcakes, give or take a few. Bake around 17-19 minutes or until a toothpick inserted in center comes out clean. Enjoy!
will lactose milk work with cake or even nut milks, i just wanted to know since one of my friends Lactose intolerant, but she will surley eat it anyways, but just in consideration, is there a possibility that there can be a substitute for it?
if you can respond back as soon as you can, it really looks like a wonderful cake to make.> ‘ – ‘ <
You could certainly experiment with nut milks, but you would also need to replace the butter to make it lactose free. Best of luck if you decide to give it a go!
Hi there,
I’m wondering about how long it took you to double-boil the egg mixture or what it looked like for the buttercream frosting? I don’t have a candy thermometer!
Thanks!
Bree
A candy thermometer is really the only way to be certain that the egg mixture has reached 160 degrees, which is the temperature needed to kill any bacteria that may be present in the egg whites.
Most grocery stores, Target, Walmart, etc will have an inexpensive candy thermometer for around $4 to $5. Or you can snag a good one on Amazon.
I made this with a different buttercream recipe (just butter, powdered sugar & vanilla) and it turned out much more pink than purple. Is that just dependent on the blackberries or could it be part of the cooking process? Would cooking the blackberry reduction less/more affect the color? My blackberries don’t seem any different than every other blackberry I’ve ever had, so I’m hoping I can do something differently to get the light purple color instead. Thanks!
I’m not sure Frannie! I made this buttercream several times during recipe testing and each batch had this same similar hue. I’m wondering if it was the difference in going with a powdered sugar based buttercream? Perhaps the different ratio of sugar/butter made the difference. Although a difference in the blackberry pigment probably makes the most sense. Hope it tasted good no matter the color! =)
This looks beautiful and I am going to make for thanksgiving. Can I substitute with gluten free flour?
This is hands down one of the prettiest cakes I’ve seen. Absolutely have to make this. It will be worth all the “Out of season prices” I’m about to pay,LOL. Thank you for sharing this.
Hi Sherry,
I would like to make this cake for my daughter’s 2nd birthday next month, but I’m afraid it will be too small. Do you have any suggestions as to using bigger round pans, making a sheet cake instead or doubling the recipe? I don’t want to mess up the ingredients and measurements.
Thanks!
Morgane
Hi Morgane! Generally speaking, you can get 12 -15 servings from an 8″ layer cake, depending on how big you cut your slices. As for baking it in a larger pan, you’ll just want to adjust the bake time according to the pan you use. Here is a helpful guide to get you started: https://www.wilton.com/cake-serving-guide/cms-baking-serving-guide.html
hi Carrie! I’m making this now for a birthday next week…I’ll be out of town until practically the last minute. I’m planning to freeze the cake and blackberry reduction and make the buttercream fresh that day. As I’m making the reduction, it looks very pink, and not purple. Was that your experience too? And when added to the buttercream it actually is purple? I’m hoping…it’s for a guy who loves purple! Pink won’t give the same experience! Thank you!
Hi Mary! I’ve made this recipe several times now each batch had a similar light lavender hue. However, some of the photos posted by our readers on social media had more of a magenta hue. I’m guessing it has to do with the pigments in the blackberries. If your batch is not purple enough for your guy who loves purple, you could add a small drop of purple gel paste to help prevent a pink cake. 😉
Dear Carrie,
I always like to make my own birthday cake. (Doesn’t matter if the celebration will be a big to-do or not.) Decided to take a little stroll online for a special recipe for my 33rd year. Came across this little gem. It’s so simple & beautiful, stopping me in my tracks. The flavor combination just whispers, delightful. It’ll be my first time making Swiss buttercream.
Thank you,
Hannah
Just made this for my sons birthday party. I switched blackberry and lime to raspberry and lemon because that’s what was more readily available and the flavors still worked great. The cake was so smooth and moist. This is also my first time making Swiss buttercream and it was sooooooo goooooood. Very happy with the way it came out! One of my guests said it was the best birthday cake she had ever had! Fun recipe, thoroughly enjoyed making and eating!
Thank you for the feedback Patrice. Raspberry and lemon sounds delicious! Happy that you’re happy!
Can you convert this to Gluten Free?
I haven’t personally made this recipe gluten free, but you could certainly substitute your favorite gluten free baking mix for the all-purpose flour. Let us know how it goes!
It’s a wonderful cake! How much would you sell for it appropriately? It’s sale price.
Sorry Dana, I’m not sure what this cake would sell for.
This cake is adorable, and you have decorated it in such unique way.
Thank you Robin!
Hello,
Can this be substituted with gluten free flour?
I haven’t personally made this recipe gluten free, but you could certainly substitute your favorite gluten free baking mix for the all-purpose flour. Let us know how it goes!
Hey Carrie, this cake has an amazing flavor!! I made it for a friend’s birthday and everyone was so impressed. But I did find it a little dry, it wasn’t overcooked. Do you have any recommendation on how to make this a bit moister or where I might have gone wrong>
I’m glad to hear you enjoyed the flavor! It could have turned out a little dry due to a heavy hand when measuring the flour, the oven temperature being a tad off (read more about that here) or even just a few minutes extra on the baking time can really make a difference (see our experiment here). Hope that gives you some ideas to troubleshoot for next time.
Hello! I’m planning to make this cake for my birthday, and I just want to double check if you really meant granulated sugar and not confection sugar for the icing, because usually confection sugar is used for icing
I made this tonight! I wasn’t entirely happy with how it came out and had a couple questions for when I try again next week.
1. What consistency should the blackberry reduction be when done? Mine was quite liquidy, very liquidy.
2. What should the reduction taste like? More tart or more sweet? Mine was quite tart and I was wondering if that was because the blackberries themselves were a bit tart. Any suggestions for how much sugar to increase, if using tart blackberries?
3. I had a hard time with the frosting, mine was too liquidy. I had to use a hand mixer as I don’t have a stand mixer. Does that affect the mixing time? I tried putting it in the fridge for about 15 minutes and it only seemed to help just a bit. I haven’t made many frostings yet, I struggle with them!
4. If I had extra blackberry reduction (and was happy with taste/consistency) do you think could I freeze it and use it the next time I made the fake?
Thanks!!
HI Carrie,
Love your recipes.
IM Vidad. I recently started a youtube channel sharing my recipes. It would be a pleasure to support me by subscribing my channel for more videos every week. https://www.youtube.com/watch?v=xIq5HkdX2ms&t=31s
Thank you 🙂
It says to take egg white to 160. They cook at 140 or is the egg supposed to be semi scrambled
Oh, we definitely don’t want scrambled eggs in the buttercream. As long as you keep whisking the eggs as they heat, you’ll be fine. All the way up to 160F.
Chef, I can’t even tell you how much I love this cake!! The blackberries, lime, blackberry whipped cream! Oh, and of course, butter!!!
I Made this yesterday with a friend of mine…it was a hit. Between me, her and her boyfriend we polished the whole thing off in one day. We loved the tartness of the cake against the sweetened cream 🙂
Hi Carrie 🙂
are these 160 degrees or F?
LOOKS AMAZING
SOPHIE 😉
160 degrees Fahrenheit 😊
I think there is an editing error in the recipe. The recipe listed above is for 3 cups of cake flour, 1 tablespoon of baking powder and 1/2 a tsp of baking soda.
However in a reply to a question about the 1 tbsp of baking powder, the reply stated that it is standard proportion to use 1 tbsp of baking powder to 3 cups of AP flour. The reply continues to indicate if cake flour is used, to eliminate the baking soda and decrease the baking powder to 2 1/2 tsp of baking powder.
I found out the hard way about this editing error when my cake sunk in the middle. It looked great until about 2/3 of the cooking time when the middle sunk. I went back through the comments to see if I did something wrong and found the reply from the author of the recipe. I make alot of cakes and have only had one cake fail like this in my 20+ years of baking.
Could you please indicate what is the correct amount for the ingredients?
Hi Kit – you are correct about the editing error. Thank you for bringing it to my attention! This recipe was updated just a few weeks ago and the error was introduced then. This cake was made using AP flour with 1 tablespoon baking powder and ½ teaspoon baking soda. If using cake flour then you’d use 2 to 2½ teaspoons baking powder and no baking soda. The recipe above is now correct again. I’m so sorry for the mixup!