Key Lime Cake

This towering three-layer Key Lime Cake is an ode to zesty key lime pie only in cake form. It’s the perfect puckery cake for any gathering.

Key lime cake slices

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.

Key lime cake slices

Simply Recipes / Cambrea Gordon

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.

key lime cake sliced

Simply Recipes / Cambrea Gordon

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.

Key lime cake slices

Simply Recipes / Cambrea Gordon

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.

Whole key lime cake

Simply Recipes / Cambrea Gordon

Storage Instructions

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

Prep Time 90 mins
Cook Time 22 hrs
Total Time 23 hrs 30 mins
Servings 16 servings
Yield 1 cake

Special equipment: three 8 or 9-inch cake pans, cardboard cake rounds, offset spatula

Ingredients

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

Garnish

  • Lime wedge

  • Lime zest

Special Equipment

  • 3 8- or 9-inch round cake pans
  • Piping bag
  • Star tip

Method

  1. Preheat the oven:

    Preheat the oven to 350°F.

  2. 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.

    Preparing baking sheet for key lime cake

    Simply Recipes / Cambrea Gordon

  3. Combine the dry ingredients:

    In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.

    Combine the dry ingredients for key lime cake

    Simply Recipes / Cambrea Gordon

  4. 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.

    Combine the wet ingredients for key lime cake

    Simply Recipes / Cambrea Gordon

  5. 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.

    Beat the eggs and sugar for key lime cake

    Simply Recipes / Cambrea Gordon

  6. 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.

    Combine the wet and the dry for key lime cake

    Simply Recipes / Cambrea Gordon

  7. 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.

    Pour cake into prepare cake pans for key lime cake

    Simply Recipes / Cambrea Gordon

  8. 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.

    Key lime cake on cooling rack

    Simply Recipes / Cambrea Gordon

  9. 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.

    Beat key lime frosting ingredients

    Simply Recipes / Cambrea Gordon

  10. 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.

    Add the lime, vanilla, and powdered sugar to finish key lime frosting

    Simply Recipes / Cambrea Gordon

  11. 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.

    Key lime cake layer on a cake round

    Simply Recipes / Cambrea Gordon

    Apply a layer of frosting to the key lime cake layers

    Simply Recipes / Cambrea Gordon

  12. 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.

    Key lime cake layer on a cake round

    Simply Recipes / Cambrea Gordon

    Apply the crumb coat to key lime cake

    Simply Recipes / Cambrea Gordon

  13. Refrigerate cake:

    Place the cake, uncovered, in the refrigerator for 30 minutes for the frosting to set. Cover and refrigerate the bowl of frosting as well.

  14. 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.

    Frost the key lime cake

    Simply Recipes / Cambrea Gordon

  15. 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.

    Make the whipped cream for key lime cake

    Simply Recipes / Cambrea Gordon

  16. 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.

    Pipe the whipped cream on key lime cake

    Simply Recipes / Cambrea Gordon

  17. Garnish cake:

    Garnish as you wish with lime wedges or rounds and sprinkle the top of the cake with lime zest.

    Whole key lime cake

    Simply Recipes / Cambrea Gordon

  18. Refrigerate and serve:

    Refrigerate the cake until ready to serve.

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Nutrition Facts (per serving)
622 Calories
30g Fat
85g Carbs
6g Protein
Show Full Nutrition Label Hide Full Nutrition Label
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Nutrition Facts
Servings: 16
Amount per serving
Calories 622
% Daily Value*
Total Fat 30g 38%
Saturated Fat 12g 61%
Cholesterol 99mg 33%
Sodium 191mg 8%
Total Carbohydrate 85g 31%
Dietary Fiber 1g 4%
Total Sugars 66g
Protein 6g
Vitamin C 6mg 32%
Calcium 70mg 5%
Iron 1mg 8%
Potassium 110mg 2%
*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.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.