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This Key Lime Cake is soft, fluffy, and packed with bright citrus flavor in every bite. Layers of tender key lime cake are filled with tangy key lime curd and finished with a creamy frosting. The best part is that all of the components can be made ahead of time. Bring this along to any summer gathering along with a pitcher of my summer rosรฉ sangria, and youโll be the life of the party, trust me.
‘Tis the season for key limes, and while I usually canโt wait to whip up my key lime pie (which is so delicious by the way), this key lime cake stole the show. If you love the sweet-tart flavor of key lime pie as I do, this cake is for you. The cake has fresh key lime zest and juice to really bring out that flavor. My favorite part is the silky key lime curd spread between the layers. And my signature cream cheese frosting pairs so well with the citrus’s brightness. This will likely be on rotation this summer, along with my bolo de coco and peach cobbler brownies. Summer is looking so sweet!
Ingredients Youโll Need for Key Lime Cake
- Key limes – You’ll use both the zest and juice throughout the cake and curd. The zest adds intense citrus flavor while the juice brings the signature tartness.
- Granulated sugar – Rubbing the zest into the sugar helps release the oils from the limes, creating a deeper citrus flavor throughout the cake.
- Egg whites – Using only egg whites gives the cake a lighter color and soft, fluffy crumb.
- Cream cheese – My favorite addition to frostings, it makes it so fluffy and creamy. The salty cream cheese balances out the sweetness so well.
- All-purpose flour – Provides structure while keeping the cake tender enough for layering.
For the rest of the ingredients, please refer to the recipe index card below!
How to Make Key Lime Cake
- Whisk together the dry ingredients.
- Rub the key lime zest into the sugar, then beat with the butter until light and fluffy.
- Mix in the oil and vanilla, then alternate adding the dry ingredients and the milk-key lime mixture until smooth.
- Divide the batter evenly among the prepared pans and bake until the tops spring back lightly and a skewer comes out clean.
- Cook the curd ingredients over medium-low heat, whisking constantly until thickened and glossy. Chill completely.
- Beat the cream cheese and butter until smooth, then add the powdered sugar, vanilla, and cream until fluffy.
- Layer the cakes with frosting.
- Pipe frosting around the edge of the layers and spread key lime curd over the center. Apply a crumb coat and chill.
- Then finish frosting and decorate with the piped key lime design.
Quick Tips for the Best Key Lime Cake
Rub the zest into the sugar. This simple step releases the citrus oils and gives the cake a stronger key lime flavor.
Use freshly squeezed key lime juice. Fresh juice provides a brighter, cleaner flavor than bottled alternatives.
Cool the cake layers completely. Warm layers can melt the frosting and make assembly difficult.
Chill the curd before assembling. Cold curd spreads more easily and stays in place between the layers.
Make-Ahead & Storage
Make Ahead: Bake the cake layers up to 2 days ahead and store tightly wrapped. The key lime curd can be prepared up to 3 days in advance and refrigerated. Fully assemble the cake up to 24 hours before serving.
Storage: After that, refrigerate for up to 4 days. Store leftovers covered with a cake dome or in an airtight container. Keep at room temperature for up to 24 hours.
If you tried this Key Lime Cake recipe or any other recipe on my website, please leave a ๐ star rating and let me know how it went in the ๐ comments below. Thanks for visiting!
Key Lime Cake
Ingredients
Key Lime Cake:
- 3 cups (390) all-purpose flour
- 2 ยฝ teaspoons baking powder
- 1 teaspoon kosher salt
- 500 grams granulated sugar
- 4 tablespoons key lime zest
- 1/2 cup unsalted butter, , at room temp
- 1/3 cup neutral oil
- 2 tsps vanilla
- 1 drop of yellow and green
- 2/3 cup milk
- 6 large egg whites
- 1/2 cup key lime juice
Key Lime Curd:
- 2 teaspoons key lime zest
- ยฝ cup granulated sugar
- 2 large egg yolks
- 2 large eggs
- 1 tablespoon cornstarch
- ยผ teaspoon kosher salt
- โ cup freshly squeezed key lime juice
Cream Cheese Frosting:
- ยพ cup (170g) unsalted butter, at room temperature
- 12 ounces (336g) cream cheese, at room temperature
- 1 teaspoon Vanilla paste or extract
- Pinch of kosher salt
- 5 cups powdered sugar
- 2 tablespoons heavy cream
Lime Decoration:
- ยผ cup cream cheese frosting
- Green food coloring gel
Instructions
To Make the Cake:
- Preheat oven to 350F. Grease and line the bottoms of three 8-inch baking pans.
- In a medium bowl, whisk together the flour, baking powder and salt. Set aside.
- In the bowl of a stand-up mixer with the paddle attachment (alternatively you can do this in a large bowl with an electric hand mixer), add the sugar and key lime zest. Beat the two together. This will release all of the fragrant oils in the lime zest and infuse them in the sugar. We want this, we need this.
- Add the butter and vanilla extract; beat until light and fluffy, about 2 to 3 minutes. Add in the oil, vanilla extract; and beat until smooth.
- If you want the cake to be a โkey lime colorโ, add a very small amount of yellow and green food coloring gel. This is of course optional.
- In a measuring cup, pour in the milk, egg whites, and add the strained key lime juice.
- Turn the mixer to low speed and, alternating between the dry ingredients and the liquid ingredients, add them to the butter/sugar mixture, until the batter is relatively smooth.
- Pour the batter evenly into the three prepared baking pans (about 470 grams of batter per pan) and smooth it out until it reaches the sides.
- Transfer the cakes to the oven to bake for 22 to 25 minutes, until a skewer inserted into the center comes out clean.
- Allow the cakes to cool in the pan for about 10 minutes and then invert onto a cooling rack and cool to room temperature. Itโll probably take a good hour for them to cool completely.
To Make the Curd:
- To a medium saucepan, add the sugar and lemon zest. Rub the key lime zest into the sugar with your fingers to release the oils.
- Then add the eggs, egg yolks, cornstarch, and salt. Whisk until combined. Then whisk in the key lime juice.
- Place the pot over medium low heat and continue whisking until the mixture thickens about 5 minutes. Then remove the pot from the heat and whisk in the butter. Strain the key lime curd into a small bowl, cover the surface with plastic wrap and refrigerate for at least 30 minutes or until completely chilled.
To Make the Vanilla Cream Cheese Frosting:
- In the bowl of a stand-up mixer with the paddle attachment (or a medium bowl using an electric hand mixer), add the cream cheese and beat it until smooth. I like to do this or else the cream cheese frosting will have little clumps of cream cheese. Next, add the butter and beat it until smooth, about 15 seconds.
- Add the powdered sugar, salt, vanilla and heavy cream. Start on slow speed so the powdered sugar doesn’t fly everywhere. And then gradually turn it to medium speed. Beat for a full 2 minutes to ensure fluffy, delicious frosting.
To Make the Key Limes for Decoration:
- In two small bowls, add about 2 tablespoons of frosting to each. You can eyeball this. One will be our key limes (lighter green) and another will be our stems (green).
- If your frosting is super soft, add about 1 tablespoon of powdered sugar to each bowl and mix it in. This will help stiffen it up.
- Add a drop or two of yellow food coloring to one frosting bowl, along with one drop of green food coloring. This will be our key limes. In the second container, add a drop or two of green food coloring gel to the second frosting bowl. Mix until smooth. Transfer the lighter green frosting to a piping bag fitted with a small round piping tip. And do the same with the second frosting.
To Decorate the Cake:
- Place one cooled cake layer on a cake board. Add about 1/3 cup of white frosting to the top of the first layer and smooth out into a thin even layer. Place the second cake layer on top. Repeat with the third layer. Add a thin crumb coat of white frosting to the cake and smooth the top and sides. Transfer the cake to the fridge to chill for about 20 minutes. Then add a second layer of white frosting to the cake.
- To add the key limes, pipe on rounds of frosting; theyโll end up looking like key limes once we add the tops. Add as many as you like. Make them any size you like, too. Dip your finger in a bit of water and tap the tops of the limes to make them appear smoother.
- Pipe on a small โVโ shape at the top of each of the limes. This will make it appear like they have a stem.
Notes
Quick Tips
Rub the zest into the sugar. This simple step releases the citrus oils and gives the cake a stronger key lime flavor. Use freshly squeezed key lime juice. Fresh juice provides a brighter, cleaner flavor than bottled alternatives. Cool the cake layers completely. Warm layers can melt the frosting and make assembly difficult. Chill the curd before assembling. Cold curd spreads more easily and stays in place between the layers.Make Ahead & Storage
Make Ahead: Bake the cake layers up to 2 days ahead and store tightly wrapped. The key lime curd can be prepared up to 3 days in advance and refrigerated. Fully assemble the cake up to 24 hours before serving. Storage: After that, refrigerate for up to 4 days. Store leftovers covered with a cake dome or in an airtight container. Keep at room temperature for up to 24 hours.Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
