Key Lime Cake

Bright, tart key lime juice brings all the flavor to the table in this key lime cake recipe. A stunning 3-layer cake perfect for a party, with fluffy lime-infused cream cheese frosting as the perfect finishing touch!

For a weekday cake when I’m craving something sweet but don’t want to overdo it, I’m all about fresh apple cake or gluten-free vegan strawberry shortcake. But for a special occasion? Well, then it’s time to bust out this homemade key lime cake recipe.

While this is a cake that looks like it came straight from a high-end bakery, I promise you it’s easier to make than you think. These days, simple cakes are in style, which works in your favor as a home baker! 

This key lime cake also tastes like it came from a bakery, with the bright flavor of key lime adding lots of zip and zing to both the moist cake layers and the irresistible cream cheese frosting. (It’s seriously hard not to eat the frosting with a spoon.) When key limes aren’t in season, regular limes will do, but key limes are extra special with their floral aroma and tartness.

Why You’ll Love This Key Lime Cake Recipe

• Something different. When you’re splurging on a slice of cake, you want it to be worth it—and to me, plain vanilla or chocolate are rarely worth it. This key lime cake is new and exciting, perfect for a special occasion or when you want to mix things up.
• Easy to make. Don’t let the fancy appearance fool you, this key lime cake is easy to make! The cake batter comes together quickly and the frosting is a simple cream cheese base with added key lime juice for flavor.
• Perfect for parties. With its vibrant flavor and impressive layers, this key lime cake is sure to wow your friends and family at any party, event, or celebration.

What You’ll Need

Scroll down to the recipe card to find the ingredient quantities and recipe instructions.

For the Cake:

• All-purpose flour – Measure this by spooning the flour lightly into the measuring cup, not scooping. This keeps you from using more flour than you need!
• Baking powder 
• Baking soda
• Salt 
• Unsalted butter – Always use unsalted butter for baking, which gives you more control over the flavor.
• Vegetable oil – Canola oil is also fine.
• Granulated sugar 
• Vanilla extract – Use pure vanilla extract, not imitation.
• Eggs – Let these come to room temperature; they’ll hold more air when beaten, giving your cake a lighter texture.
• Buttermilk – This should also be room temperature. Buttermilk reacts with the baking soda to create extra rise.
• Milk – Any kind you have on hand.
• Key limes – You’ll need both the juice and the zest; zest first, then juice.

For the Frosting:

• Cream cheese – Use the full-fat cream cheese that comes in blocks, not plastic tubs.
• Unsalted butter
• Powdered sugar – Also known as confectioners’ sugar.
• Key limes – For the juice, zest, and some slices for garnish. 

What Can I Substitute for Key Lime Juice?

If key limes are unavailable, you can substitute with an equal amount of regular lime juice. For a different spin on this recipe, lemon juice would also work to make a bright and tart lemon layer cake.

How to Make Key Lime Cake

• Prepare. Preheat your oven to 350°F and grease three round cake pans with butter. 
• Combine the dry ingredients. In a medium mixing bowl, whisk together the flour, baking powder, baking soda, and salt.
• Combine the wet ingredients. Cream the butter, oil, sugar, and vanilla in another mixing bowl, until they’re fluffy and lighter in color. Beat in the eggs one at a time. 

• Put it all together. Mix half of the dry ingredients into the wet ingredients. Slowly mix in the buttermilk, followed by the milk. Mix in the key lime juice and zest, then the remaining dry ingredients. 
• Bake. Divide the batter evenly between the cake pans. Bake for about 23 minutes, or until a toothpick inserted in the center comes out clean. 
• Cool. Remove the cakes from the oven. Let them cool in the pans for 10 minutes, then turn them out onto wire racks to finish cooling. 

• Make the frosting. Beat the cream cheese and butter on medium speed until well combined. Reduce the mixer speed to low; beat in half of the powdered sugar, followed by the key lime juice and zest. Then, beat in the remaining powdered sugar. 
• Assemble the cake. Set a cake layer onto a serving platter and spread 1 cup of frosting over the top. Add another cake layer over the frosting and spread another cup of frosting over that layer. Repeat with the last cake layer and more frosting. 
• Frost and decorate. With the remaining frosting, frost the outside of the cake and pipe swirls around the top edge. Sprinkle the top of the cake with zest and garnish with lime slices.   

Tips for Success

• Room temperature ingredients are key. Make sure your eggs, buttermilk, and milk are at room temperature before baking to ensure a light, airy cake. This goes for the butter and cream cheese for the frosting, too—room temperature ingredients mix together more smoothly and evenly.
• Level the layers if needed. Cakes naturally dome in the center during baking, which can become very noticeable when you’re stacking three layers on top of each other. Bake-even strips, which fit around the cake pans, can prevent this from happening, but if you don’t have them, you may want to level the layers if you notice doming. To do this, use a serrated knife and gently, VERY carefully saw off the domed top from each cake layer.
• Let the cakes cool completely. Before assembling and frosting, make sure the cake layers are fully cooled to prevent melting or sliding frosting.
• Use the right tools for frosting. To get the smooth frosted appearance on the sides, use either an offset spatula or a bench scraper. For the swirls on top, use a piping bag with a star tip.

Variations

• Try another frosting. Vanilla buttercream or a coconut-flavored frosting would also work well with this key lime cake.
• Put your own spin on the decorating. For an even easier, visually simpler cake, press white chocolate shavings or toasted coconut into the frosting on the tops and sides of the cake. Want to put your piping skills to the test? Make extra frosting and add extra rosettes or other flourishes to your cake.
• Make it gluten-free. Substitute the all-purpose flour with a measure-for-measure gluten-free flour. Don’t use a single gluten-free flour, like almond flour or coconut flour, or the key lime cake won’t turn out.

How to Store

Once the key lime cake is frosted, it can be covered with a cake keeper or an inverted bowl or large pot to protect it from air exposure. Because of the cream cheese in the frosting, this cake shouldn’t be left at room temperature for more than 2 hours; after that, it needs to be refrigerated. It will last about 5 days in the fridge. Allow the cake to come to room temperature before serving for the best flavor and texture.

Can I Freeze This Recipe?

Yes, you can freeze this key lime cake for later! Both the unfrosted cake layers and the frosted cake freeze well. 

To freeze the cake layers, wrap them individually in plastic wrap once completely cooled, then place them in a zip-top freezer bag, squeezing out as much air as possible before sealing. They can be frozen for up to 3 months. Thaw the layers at room temperature before frosting. 

If you've already assembled and frosted your cake, place it in the freezer for about an hour to harden the frosting first. Then, wrap the entire cake tightly in plastic wrap and a layer of aluminum foil. When you're ready to enjoy, remove the cake from the freezer, unwrap it, and let it thaw in the refrigerator overnight. 

More Cake Recipes

• Gluten-Free Gingerbread Cake
• Crepe Cake
• Flourless Dark Chocolate Cake
• Apple Upside Down Cake (Gluten-Free)
• Cranberry Orange Coffee Cake