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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
Natasha Kravchuk
Hi! I'm Natasha Kravchuk. Here you'll find delicious, trusted recipes with easy step-by-step photos and videos. 
Hi Natasha! searched and but didn’t see if this will work for a sheet cake. I’m making this for my niece’s birthday and we’re serving about 13 people. Thank you for sharing your amazing recipes!
Hi Huong, I have not tried this in a sheet pan myself to advise. If you happy to try it out, I would love to know how you like it.
It’s sooooooooo delicious this cake…. so light and such a refreshing taste. The icing is just so amazing. Thank you Natasha. Will be making this again and again and again…
You’re so very welcome!
This cake was a hit at a party……so good – the recipe is a keeper. It is super important to beat those eggs for the sponge cake – I used a hand mixer and should have beat them longer – my cakes were a bit flatter then the video. I only did two layers and they soaked up all of the syrup without becoming soggy. The frosting is so wonderful – tangy and light! First time for using sour cream in a frosting but it works!
I’m so happy you enjoyed that. Thank you for sharing that with us, Ann!
Made a sponge base following recipe and watched the tutorial. Instead of two thick cakes I got two thin and had to bake another batch. Other than that, cake came out absolutely delicious.
so light , bright and delicious . i used Key lime juice in this recipe instead of the limes. it worked out great.
Thank you for sharing, Suzanne!
Great recipe. Love the flavor. my first attempt failed so tried a second time right away within an hour even with cold eggs. I found that i had to beat the egg batter until it turns white pale and thick and to fold the flour gently from the center to the side. If the egg batter is thick but not white pale, it will deflate. The second batter rose beautifully and light :).
Thank you so much for sharing that with me, Yen!