Key Lime Cake is a pleasant mouth-puckering cake bursting with vibrant lime flavor.
The towering three-layer cake is an ode to the little and lovable key lime as it includes both the zest and the juice from this citrus fruit. Like Key Lime Pie, this cake finds the right balance between sweet and sour, and tart and creamy.
There’s nothing subtle about the citrusy zing in this cake. Not only is it loaded with key lime zest, but the zest is rubbed into the sugar before mixing the cake, to infuse it with flavorful essential oils. And to really put the sweet-tart balance in the limelight, the cake is frosted with tangy key lime cream cheese frosting.
Speaking of limelight, this is an excellent cake for celebrating birthdays and special occasions. Consider this cake a weekend project, with all of the zesting, juicing, and decorating, but it shouldn’t be difficult to enlist some helpers when frosting and whipped cream are involved.
What Are Key Limes?
C. aurantiifolia, known as key lime or Mexican lime, is a wonderfully tart lime prized for its aromatic, floral flavor. It's the indispensable ingredient for Key Lime Pie and in this sharp Key Lime Cake. Compared to standard Persian limes, key limes tend to be smaller, have a stronger aroma, a thinner rind, and sharper acidity.
Key limes can be difficult to find; so, if you don’t have any, don’t sweat it. C. latifolia, or Persian limes, which are more commonly cultivated in the US, are bigger and easier to juice. And they have fragrant zest as well. They may not have as much acidity, but they’ll still give this cake a balanced lime flavor.
How to Make Key Lime Cake
Not only is this cake moist and flavorful, but it's also simple to mix. This recipe uses vegetable oil instead of butter, which makes the cake incredibly moist and tender. Butter may be more flavorful than oil, but in this case, the butter would compete with the lime flavor. This also means you save time since you don't need to cream butter and sugar together.
Start by rubbing the zest into the sugar, infusing the sugar with the oils from the limes. Remember when zesting citrus to use just the outer skin, not the white pith, as the pith is too bitter. Add the eggs to the sugar and beat until smooth and creamy.
Alternate adding the dry and wet ingredients, beginning and ending with the dry. This mixes the batter evenly and prevents lumps from forming. It also avoids overdeveloping the gluten in the flour, which would make the cake tough.
Can I Use A Different Sized Cake Pans?
You can bake the cake in 8-inch or 9-inch pans and with two or three layers. Just adjust your baking time accordingly.
- Three 9-inch layers will bake in about 18 minutes
- Three 8-inch layers may take about 22 minutes
- A two-layer cake will take longer to bake. I'd suggest checking for doneness after about 30 minutes.
How to Make Key Lime Cream Cheese Frosting
A room-temperature block of full-fat cream cheese is best for this frosting. The cream cheese sold in a plastic tub or low-fat cream cheese has a higher moisture content results in a runny frosting, especially considering this frosting also has a splash of fresh lime juice.
To get the smoothest cream cheese frosting, first, mix the cream cheese and butter together into a uniform mixture. Then add the rest of the ingredients and mix until creamy and smooth. If the frosting is too soft, place it in the refrigerator for 10 minutes. If it’s still too runny after chilling, add more powdered sugar, about 1/2 cup (113g) at a time.
How to Make Whipped Cream from Scratch
The top of the cake is decorated with rosettes of homemade whipped cream.
For the easiest whipped cream, make sure the cream is cold. You can also chill the bowl and whisk in the freezer or refrigerator before whipping.
Keep a watchful eye on the cream as you whip it. If it gets overwhipped, the milk solids may separate, essentially making sweetened butter instead of luscious whipped cream. Sometimes I like to stop the mixer early and finish whisking by hand just to be sure.
Make Key Lime Cake Ahead of Time
The cake layers can be made ahead of time and assembled before serving. After baking, allow the layers to cool completely, then wrap them in plastic and store them at room temperature overnight, or freeze them for longer storage. The layers will last in the freezer for up to 3 months.
The frosting can also be made in advance and stored in an airtight container in the refrigerator for up to 5 days. Before frosting the cake, let the frosting warm up at room temperature for 10 to 15 minutes and stir until smooth.
The cake will keep in the refrigerator, covered, for up to 4 days. After slicing into it, I like to place a piece of plastic wrap or some parchment paper onto the exposed cake layers to prevent them from drying out.
More Mouth Puckering Citrus Dessert Recipes
Key Lime Cake
Special equipment: three 8 or 9-inch cake pans, cardboard cake rounds, offset spatula
For the key lime cake
3 cups (360g) all-purpose flour
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon kosher salt
3/4 cup (170g) sour cream
1/3 cup (80ml) fresh key lime juice
2/3 cup (180ml) vegetable oil
2 cups (400g) granulated sugar
2 tablespoons key lime zest
1 teaspoon vanilla extract
4 large eggs
For the key lime cream cheese frosting
1 (8-ounce) package full-fat cream cheese, softened
1/2 cup (113g) unsalted butter, softened
1/8 teaspoon kosher salt
1 tablespoon key lime juice
1 tablespoon lime zest
1 teaspoon vanilla extract
5 1/2 cups (620g) powdered sugar
For the whipped cream
1 cup (240ml) heavy cream
2 tablespoons (14g) powdered sugar
1 teaspoon vanilla extract
- 3 8- or 9-inch round cake pans
- Piping bag
- Star tip
Preheat the oven:
Preheat the oven to 350°F.
Prepare the pans:
Grease three 8- or 9-inch round cake pans with butter. Line the pans with parchment paper and grease the parchment. Dust the bottom and sides of the pans with flour and tap out the excess.
Combine the dry ingredients:
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
Combine the wet ingredients:
In a small bowl or a liquid measuring cup, whisk together the sour cream, key lime juice, and vegetable oil until combined.
Beat the eggs and sugar:
In the bowl of a stand mixer, add the lime zest and sugar. Using your hands, rub the key lime zest into the sugar to release the oils in the zest.
Set the bowl in the base of your stand mixer and fit the mixer with the paddle attachment. Add the eggs and vanilla extract and beat the mixture on medium speed until smooth and creamy, about 1 minute.
You can also do this in a large mixing bowl and use an electric hand mixer.
Combine the wet and the dry:
Add one third of the flour mixture into the egg mixture and beat on low speed until incorporated. Pour in half of the sour cream mixture and beat just until combined.
Continue alternating the dry and wet ingredients, making sure to end with the dry ingredients and mixing until just combined and the ingredients are incorporated.
Use a rubber spatula to scrape down the bowl in between additions to ensure the batter mixes evenly.
Bake the cake:
Divide the batter evenly among the three prepared cake pans. Bake for 18 to 22 minutes, or until a toothpick inserted in the center of the cake comes out clean. The edges of the cake will be golden and will start to pull away from the sides of the pan. The cake should spring back when gently poked with your finger.
Cool the cake layers:
Let the cakes cool in the pans for 15 minutes, then turn them out onto a wire rack to cool completely before frosting.
Make the frosting:
In a stand mixer fitted with the paddle attachment, or in a large mixing bowl with a hand mixer, beat the cream cheese, butter, and salt on medium speed until smooth, about 2 minutes.
Add the lime, vanilla, and powdered sugar:
Add the key lime juice and zest, vanilla extract, and powdered sugar. Mix on low speed until combined, then increase the speed to medium and continue mixing until smooth and creamy, about 2 minutes. The frosting will be much thicker than standard buttercream frosting.
If the frosting seems too soft, place it in the refrigerator for 10 minutes to stiffen. If it still seems too runny, add more powdered sugar, 1/2 cup at a time, until you reach the desired consistency.
Apply a layer of frosting to the cake layers:
Place one of the cake layers right-side-up on a large plate or cardboard cake round at least 2 inches larger than the cake. Use an offset spatula or a butter knife to spread a thick layer of frosting, 1/2 to 1 cup, evenly over the layer.
Add another cake layer and spread another layer of frosting. Top with the remaining cake layer, placed up-side-down, so the top of the cake is smooth and flat. Make sure that the cake layers are centered and the top of the cake is level.
Apply the crumb coat:
Spread a generous amount of frosting over the top and sides of the cake using an offset spatula or the straight edge of a large butter knife. Use the spatula to spread the frosting into a thin, even layer. You should be able to see the cake through the frosting.
This thin layer of frosting is called the crumb coat and helps catch any loose crumbs on the outside of the cake so that the final layer of frosting doesn't have any crumbs caught in it.
Place the cake, uncovered, in the refrigerator for 30 minutes for the frosting to set. Cover and refrigerate the bowl of frosting as well.
Frost the cake:
Remove the cake and the bowl of frosting from the refrigerator. Stir the frosting to smooth it out.
Spread a generous amount of frosting over the top and sides of the cake as before, this time leaving a thicker layer of frosting. Use the offset spatula or the back of a butter knife to smooth the sides.
Make the whipped cream:
In the bowl of a stand mixer fitted with a whisk attachment, or in a large mixing bowl with a hand mixer, whip the heavy cream, powdered sugar, and vanilla to stiff peaks on medium-high speed, about 3 to 4 minutes. Stiff peaks stand straight up on the beaters when lifted out of the whipped cream.
Pipe the whipped cream:
Use a piping bag fitted with a large star tip to pipe 12 rosettes of whipped cream along the top edge of the cake.
Garnish as you wish with lime wedges or rounds and sprinkle the top of the cake with lime zest.
Refrigerate and serve:
Refrigerate the cake until ready to serve.
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|Nutrition Facts (per serving)|
|Amount per serving|
|% Daily Value*|
|Total Fat 30g||38%|
|Saturated Fat 12g||61%|
|Total Carbohydrate 85g||31%|
|Dietary Fiber 1g||4%|
|Total Sugars 66g|
|Vitamin C 6mg||32%|
|*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.|