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.
Hi. Can I make the blackberry reduction ahead of time and store it in the fridge until I’m ready to make the buttercream? My husband is going to love this cake <3.
Where does one get the edible flowers et cetera? Do you just use flowers from a garden or do you order them someplace special? Thanks!
Ounces volume or ounces weight?
My daughter and I baked this twice (I bake, she decorates), and it turned out beautifully both times.
A couple of notes from our experience:
1. It’s worth it to double the blackberry reduction. We definitely wanted that blackberry tartness between the layers. I used frozen blackberries for that because they were *much less expensive.
2. Make sure your house is nice and cool when working with the buttercream. I found that 72F was good. We keep our house at 78F during the summer, and the first time my daughter found herself working with frosting that was way too soft. Lower the ambient temperature made a HUGE difference the second time. I never realized that we hadn’t done serious buttercream work during the summer before.
Thanks for the great recipe =)
I made this cake for a picnic gathering, and it went over very well…everyone absolutely loved it! I am making this recipe again this weekend, but making cupcakes instead of cake. I’m going to cut a small hole in each and pipe some of the blackberry frosting inside. Then I will decorate with Russian tips. Here’s hoping they turn out good!
Can I use frozen blackberries for this cake?
I’m wondering if you have experimented with high altitude baking at all. Would love to make this for a friend’s baby shower next week but we live at 7200 ft and some things just don’t work here. Thanks!
Can I make this cake 2 days before the party? Plans to put fresh blackberries in between layers….and how do you keep the flowers fresh if you order it few days before the party? Thanks in advance.
Well dang. I am making the blackberry reduction right now, and it’s a vibrant brick red – it’s very very red. Is this right? I can’t imagine mixing this into the frosting will turn cool purple lavender. Any tips???