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This key lime cake is the ultimate summer party cake. It’s pummeled with crunchy toasted coconut and boasts the juice from 5 limes. The punch of lime juice and zest is refreshing and so tasty. We loved the delicate, fluffy and moist cake layers. Plus it’s not overly sweet. This is a highly enjoyable cake! It also refrigerates and freezes well.
One of my readers, Lena shared this recipe with us using our 4-ingredient sponge cake as a base. She described it as “A bite of heaven. Super moist, airy, light and the sour cream really adds to the lightness and tartness of the cake.” I couldn’t agree more.
The frosting is brilliant! Lana, thank you so much for sharing this with us :). P.S. Lana shared that this cake works beautifully with gluten free flour for those with dietary restrictions, which is so great to know!
Watch How to make Key Lime Cake:
Grab a tiny bag of popcorn and enjoy this 4 minute video recipe!
Now go forth and make Key Lime Cake! I hope you enjoy these video recipes. We love making them for you! 🙂
Print The Key Lime Cake Recipe ↓↓↓
Key Lime Coconut Cake
Ingredients
1 Recipe for Sponge Cake (makes two 9-inch cakes)
- 6 large eggs, room temperature
- 1 cup granulated sugar
- 1 cup all-purpose flour
- ½ tsp baking powder
Key Lime Syrup Ingredients:
- 1/4 cup freshly squeezed lime juice, from 3 medium limes
- 3 Tbsp granulated sugar
- 3/4 cup warm water
Key Lime Frosting Ingredients:
- 8 oz cream cheese, softened
- 1 cup granulated sugar
- 16 oz cold sour cream, full fat
- 3 Tbsp lime juice, freshly squeezed (from 2 medium limes)
- 1 Tbsp lime zest, from 2 medium limes
Topping Ingredients:
- 2 cups 7 oz sweetened shredded coconut
Instructions
How to Make Key Lime Cake:
- Toast coconut at 350˚F in a small baking pan in oven, stirring a few times, especially towards the end, until golden and dry, 7 to 10 minutes. Set aside to cool.
- Make 4-Ingredient Sponge Cake and set aside to cool. Get the recipe on natashaskitchen.com and be sure to watch the video tutorial.
How to Make Key Lime Frosting:
- In the bowl of your mixer fitted with whisk attachment, beat together cream cheese and 1 cup sugar on high speed 3 minutes until whipped, scraping down the bowl as needed.
- Beat in 16 oz cold sour cream until smooth (1 min on high). Add lime zest and juice and beat to combine (1 minute on high). Refrigerate frosting if not using right away.
How to Make Key Lime Cake Syrup:
- In a measuring cup, combine 1/4 cup fresh lime juice, 3/4 cup warm water and 3 Tbsp sugar. Stir to dissolve the sugar and set aside.
How to Assemble Key Lime Cake:
- Slice cake layers in half with a serrated knife. Place the first layer, cut-side-up on a cake platter. Brush with 1/4 of the lime syrup. Top with a generous amount of cream. Repeat with remaining cake layers then cover the entire cake with remaining cream.
- Cover the entire cake generously with toasted and cooled coconut flakes, using your hands to scoop coconut onto the sides, pressing gently to adhere. The coconut flakes are crispiest if served right away but it is easier to slice the cake once it's had a chance to set in the refrigerator for about 2 hours.
Notes
If you make this recipe, I’d love to see pics of your creations on Instagram, Facebook and Twitter! Hashtag them #natashaskitchen
First tasted this cake at a Florida BBQ and was sold.
Came home to NZ and recreated it for my sisters birthday, it was divine and I got so many compliments! Zesty, moist, light and not too sweet.
Perfection, thank you!
It is a wonderful cake. So glad it was enjoyed. Thank you for the review.
It works well with lemon too – I added lots more zest into the icing and used just lemon juice and sugar in the syrup (no water).
Thank you so much for sharing that with me.
Done this few times now, once I used lime and lemons (didn’t have enough lime) and used a little less sugar (I always cut down for all recipes, even sponge) and my family liked it better. This week made using only lime and some said it was divine :D, so thank you for sharing it, its a great cake
You’re welcome! I’m so happy you enjoyed it, Dov!
I’m a Canadian and the fullest fat sour cream we have here is 14%. Do you think my frosting will be runny? Is there anything else I can add to the frosting to help thicken it?
Hi Nancy, Canadian sour cream has a different consistency typically than US sour cream and it is runnier. I suspect that type of sour cream will not work well in this frosting or it will be runny.
Hi Nancy,
Fellow Canadian here. I found the full fat sour cream in the yellow no name container from Great Canadian Superstore is nice and thick and works well in recipes such as these.
You can buy Gay Lea Gold sour cream. It is high fat content and very thick.
As to your previous comment about using full fat to the previous commenter, I used full fat and as she said pancake batter. I also kept my bowl, utensils cold!!! Just not a good frosting.
Was wondering how to thicken my frosting. Used cream cheese, sour cream and sugar like recipe and it’s like pancake batter. Stuck in fridge even added corn starch and still nothing. I’ve never seen this happen.
Hi Mary, if you use a loose or low-fat sour cream, that can happen. The frosting isn’t overly thick (it’s not pipeable) but also should not be like pancake batter.
A party in my palette!
Thank you
I’m so glad you enjoyed it!
Hi Natasha,
I LOVE your recipes!
I want to make this cake, what do you think if I add lemon extract to the frosting or the batter?
Thanks,
Mariya
I’m so glad you enjoyed that, Mariya! I bet that could work! If you experiment, I would love to know how you like that.
Hi Natasha, I tried making this and so far it looks fantastic! But my frosting is looking pretty runny and liquid-y. Is it supposed to be like that? Will it set if I refrigerate it for a while?
Hi Bea, the frosting is very soft, but should not be runny or liquid. I wonder if maybe you oversoftened the cream cheese. Also, make sure to use a regular thick sour cream. There are some varieties that can be runny like Canadian sour cream.
HI natasha … i love your recipes.. i really want to try this cake recipe. However, i seem to dont find any sour cream…can i use any other ingredients in place of sour cream?
Hi Jess, I honestly haven’t tried anything else but if I had to substitute, I would try a full fat, plain Greek yogurt first since it is similar in consistency and flavor. Again, I haven’t tested it but that would be my best guess.
Thanks natasha for your reply ..wll try it out thanks again
Dear Natasha,
Could you please provide metric measurements (grams)? I would love to bake this beautiful cake.
Hi Kristina, We are currently working on adding metric measurements to all of our recipes but it is taking some time as we have to add them one at a time. Thank you so much for being patient! In the meantime, check out our post on measuring which should help
Dear Natasha!
I made this cake yesterday. It’s divine! I made so many of your cakes, and they ALL turned out gorgeous and delicious! I’m so grateful to you. Thank you so much for your hard work!
Thank you for that wonderful compliment, Yelena!
Natasha, thanks for another wonderful recipe – came out perfect!!! I have a question though… do you think there’s a way to cut out some sugar without compromising the taste/texture too much? For instance, could i use less sugar in sponge cake recipe/syrup/frosting?
P.s. i also added some dark rum on layers, and it gave the cake a decadent flavor boost 🙂
Hi Jenya, Sugar allows the cake to retain moisture and aeration without going stale too quickly, altering that may affect the texture. That dark rum add on sounds tasty! Thanks for the awesome review!
Thank you Natasha! I made this cake 2 days ago for a birthday celebration and it was perfection! Light, moist and not too sweet! It was my first time making a biskvit, came out so well. Two days later it’s fresh and tasty, and I’m still getting compliments on the “most delicious cake”. Your recipes are always the best!
You’re welcome Tanya! I’m glad to hear how much you enjoy the recipe. Thanks for sharing your excellent review!
Can you please make the recepies also with gram indication? it never Comes out correct when I convert.
Hi Arthi, we have been working on adding the gram measurements in more recent recipes but with 800+ recipes, we honestly just haven’t found time to go through and convert every recipe in the archives. We may just need to hire someone to do that for us :).
This cake was amazing and very easy to make . I wish I could upload a picture. Thanks Natasha!
I’m happy to hear that Blair! I would love it if you joined our private Facebook group where you can share your yummy photos!!
Hey Natasha! I love your recipes! I wanted to make a 3 tiered cake for fathers day, how can I adjust the amount of batter? Thank you so much! 😘
Hi Mohi, you will have to estimate for various cake pan sizes. I have only experimented with this using a 9″ round cake pan or a 9×13 or a sheet pan.
Hi Natasha your recipes are amazing this key lime cake came out so well everybody loved it. can you please teach us how to make the best Red velvet cake.
Thank you,
Stay blessed.
Thank you for the suggestion! If I come up with something great, I will be sure to share it 🙂
I have used the filling recipe once before and found that the juice of 3 large limes
was sufficient.
Can I use a regular key lime cake mix and if so could that be frozen too.
Hi Sharon, I’ve never tried freezing a cake from store-bought cake mix so I’m not sure how that would work. Also, the syrup would probably make a cake mix cake a little soggy. This sponge cake takes on moisture really well and doesn’t get soggy for days – we’ve had leftover slices refrigerated for up to 3 days and it was still enjoyable then 🙂
Natasha, have you tried this recipe with real key limes? Do you think it would be to tart?
Hi Lee, Hmmm… it might be with that much fresh lime juice..