Let me introduce you to a sunshine-soaked showstopper: Key Lime Coconut Cake. Every bite of this irresistible confection is a vacation for your tastebuds, blending ultra-moist sponge cake, tangy lime syrup, dreamy cream cheese frosting, and a glorious crown of toasted coconut. This is the kind of cake that turns an ordinary day into a celebration. Whether you’re baking for a special occasion or simply treating yourself, Key Lime Coconut Cake brings a bit of the tropics into your kitchen, one luscious forkful at a time.

Key Lime Coconut Cake Recipe - Recipe Image

Ingredients You’ll Need

The beauty of this Key Lime Coconut Cake lies in its straightforward ingredients—each bringing essential flavor, texture, and brightness to the table. Don’t be tempted to swap or skip; every component has a delicious role to play in this layered masterpiece.

Eggs (6 large, room temperature): They give the sponge cake its light, airy structure and create a stunningly soft crumb.
Granulated sugar (1 cup for cake, 3 Tbsp for syrup, 1 cup for frosting): It sweetens and helps achieve a smooth, creamy frosting; a touch in the syrup keeps everything balanced.
All-purpose flour (1 cup): The essential foundation for a stable, tender cake layer.
Baking powder (½ tsp): Adds just the right lift for a fluffy sponge.
Freshly squeezed lime juice (¼ cup for syrup, 3 Tbsp for frosting): Use real limes—the zingy tartness wakes up every bite!
Warm water (¾ cup): Helps dissolve the sugar and mellow out the syrup.
Cream cheese (8 oz, softened): The secret to a rich, tangy frosting that cuts through the sweetness.
Sour cream (16 oz, cold, full-fat): Keeps the frosting light and silky—no heaviness here.
Lime zest (1 Tbsp): Intensifies the citrus aroma and adds beautiful flecks of green in the frosting.
Sweetened shredded coconut (2 cups): Toasted for maximum flavor and crunch—it’s the ultimate tropical touch.

How to Make Key Lime Coconut Cake

Step 1: Toast the Coconut

Preheat your oven to 350°F (175°C). Spread the shredded coconut evenly on a small baking pan. Slide it into the oven and toast for 7 to 10 minutes, stirring halfway through. Watch closely—coconut loves to go from toasted to scorched in seconds! Golden and fragrant, this layer brings irresistible crunch and rich flavor to your Key Lime Coconut Cake.

Step 2: Prepare the Sponge Cake

Follow the classic four-ingredient sponge cake method: whip the eggs with sugar until pale and volumized, fold in the flour and baking powder gently, and bake until springy. For a video walkthrough, visit natashaskitchen.com, then let the cakes cool completely. Patience here is key—the cooler your cake, the easier it will be to slice and layer later.

Step 3: Whip Up the Key Lime Frosting

In a stand mixer or using a handheld mixer, beat the softened cream cheese with sugar on high until it’s fluffy and light—scrape the bowl as you go to ensure a smooth base. Mix in the cold sour cream, beating just until fully blended, then finish with lime juice and zest. This frosting is a punchy, creamy dream that almost steals the show. If not assembling right away, pop it in the fridge.

Step 4: Make the Key Lime Syrup

Combine freshly squeezed lime juice, warm water, and sugar in a measuring cup, stirring until the sugar dissolves completely. This quick syrup will soak into the sponge, infusing every bite of your Key Lime Coconut Cake with that signature burst of citrus.

Step 5: Assemble the Key Lime Coconut Cake

Once your sponge cake is completely cool, slice each layer horizontally to create four even tiers. Place the first layer cut-side-up onto your cake stand or platter, generously brush with a quarter of the lime syrup, then spread on a thick layer of lime frosting. Repeat the process, stacking, brushing, and frosting, until all layers are assembled. Cover the top and sides with the rest of the frosting.

Step 6: Finish with Toasted Coconut

Take your pile of toasted coconut and, with clean hands, gently press it onto the top and sides of the cake. This tactile step is as fun as it is tasty—the coconut sticks to the creamy frosting in beautiful, fluffy mounds. When you’re done, refrigerate your Key Lime Coconut Cake for a couple of hours to set, making it easier to slice and helping the coconut remain perfectly crisp.

How to Serve Key Lime Coconut Cake

Garnishes

For an extra flourish, sprinkle a little extra fresh lime zest over the finished cake just before serving or nestle a few thin lime slices on top. A scatter of delicate edible flowers can transform this dessert into an elegant centerpiece for your table.

Side Dishes

Since Key Lime Coconut Cake packs a bold, tropical punch, serve it with fresh berries, a simple fruit salad, or a scoop of tart raspberry sorbet for a refreshing contrast. Freshly brewed coffee or an iced coconut-lime mocktail will set the mood for a mini vacation in every bite.

Creative Ways to Present

Try baking the batter in a sheet pan, cutting it into cute squares, and adorning each one with coconut for lovely individual treats. Or assemble as a naked layer cake and pile on extra fruit for a relaxed, rustic style—no matter how you present it, Key Lime Coconut Cake will always draw rave reviews.

Make Ahead and Storage

Storing Leftovers

Wrap any leftover Key Lime Coconut Cake tightly in plastic wrap or keep it in an airtight container in the fridge. It’s best enjoyed within three days while the coconut stays crisp and the frosting remains fresh.

Freezing

You can freeze slices or even the full cake—just wrap each piece well in two layers of plastic, then foil, and stash in the freezer for up to a month. Let thaw overnight in the fridge before serving, to maintain the cake’s cloud-like texture.

Reheating

This cake is best served chilled or at cool room temperature. Avoid microwaving, as it can make the frosting runny and affect the coconut’s crunch. If you take the cake out of the fridge, allow it to sit for 10 to 15 minutes to soften slightly before slicing.

FAQs

Can I use regular limes instead of Key limes?

Absolutely! While Key limes have a distinctive tartness and floral aroma, regular (Persian) limes work beautifully for the Key Lime Coconut Cake. The flavor will be slightly less sharp but still utterly delicious.

Can the coconut be left untoasted?

You can use plain shredded coconut, but toasting really intensifies the flavor and adds a caramelized crunch that takes the cake over the top. Give it a try—you won’t regret those golden edges!

What’s the best way to slice this cake?

Use a long, sharp serrated knife, wiping it clean between cuts to keep those beautiful layers neat. Chilling the cake before slicing helps, too, so every slice looks bakery-worthy.

Can I make the cake and frosting in advance?

Definitely. The sponge, syrup, and frosting can each be made up to a day ahead and stored separately in the fridge. Assemble the cake a few hours before serving for best flavor and texture.

Is there a gluten-free option for Key Lime Coconut Cake?

Yes! Substitute your favorite 1:1 gluten-free all-purpose flour blend for the regular flour in the sponge. All other ingredients remain naturally gluten-free, making it perfect for sharing with more friends.

Final Thoughts

If you’re ready to channel a bite of island sunshine right into your kitchen, this Key Lime Coconut Cake is your ticket. It’s bright, luscious, and absolutely unforgettable—perfect for a celebration or just because. Don’t hold back: gather your limes, toast your coconut, and watch those smiles appear with every slice!