Key Lime Cake

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.

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 Pie
• Lime Icebox Cookies
• Triple Layer White Cake with Orange Curd
• Classic Lemon Bars
• Lemon Cheesecake