Key Lime Cake Recipe

Table of Contents

The Only Key Lime Cake Recipe You’ll Ever Need | Sunshine in a Slice

A Taste of Sunshine

I’ll never forget my first real Key lime pie, eaten at a rickety table with the salt air tangling my hair. It was a perfect balance of bracing citrus and creamy sweetness, a memory I’ve chased ever since. This Key Lime Cake is my homage to that moment. It captures that same bright, sunny essence but in a soft, tender crumb, enveloped in a cloud of tangy cream cheese frosting. It’s not just a dessert; it’s a slice of pure, unadulterated joy, guaranteed to lift your spirits with every forkful.

Why You’ll Love This Key Lime Cake

It’s a Burst of Happy, Balanced Flavor: The cake isn’t overly sweet. The vibrant, aromatic lime zest and juice cut through the richness, creating a sophisticated flavor profile that delights the palate without overwhelming it.
An Unforgettable, Melt-in-Your-Mouth Texture: The combination of oil and buttermilk creates an incredibly moist and tender crumb that practically dissolves on your tongue, a perfect contrast to the velvety frosting.
Surprisingly Simple to Make: Don’t let the layers fool you. This is a straightforward, no-fuss cake recipe. The method is simple, and the result looks impressively professional.
Your New Signature Dessert: This is the cake people will request for birthdays, potlucks, and summer gatherings. It’s a memorable showstopper that feels both special and comforting.

I brought this cake to a neighborhood barbecue once, tucked amongst the brownies and chocolate chip cookies. My neighbor’s son, a famously picky eater who generally regards anything green or unfamiliar with deep suspicion, eyed it warily. After some coaxing, he took a small bite. Then a bigger one. He finished the entire slice and quietly asked if there was more. His mother looked at me as if I’d performed magic. It was the ultimate testament to this cake’s universal, irresistible appeal.

What Makes It Special

The magic of this cake lies in its ingredients. Each one plays a crucial role in building that perfect flavor and texture.

Fresh Lime Zest & Juice: This is non-negotiable. The zest is where the powerful, aromatic citrus oils live, and the fresh juice provides that essential tang. Bottled juice simply can’t compare.
Canola or Olive Oil: Using oil instead of butter guarantees an exceptionally moist crumb that stays tender for days, avoiding any risk of dryness.
Whole Milk & Eggs: These provide the rich structure and luxurious mouthfeel that makes each bite so satisfying.
The Tangy Frosting Duo: The combination of creamy, tangy cream cheese and rich butter creates a frosting that is lush but not cloying, perfectly complementing the zesty cake.

Making It Happen: Baking Your Sunshine Cake

First, preheat your oven to 325°F (165°C). This slightly lower temperature ensures the cakes bake evenly without doming too much or browning too quickly. Generously grease two 9-inch or three 8-inch round cake pans and line the bottoms with parchment paper for foolproof release.

Now, let’s make the batter. In a large bowl, we’ll whisk together the wet ingredients. Pour in the canola oil, then crack in the eggs, and add the whole milk. Now, for the star of the show: grate in the vibrant green lime zest and squeeze in that fresh, tart juice. Whisk this all together until it’s a smooth, pale yellow liquid.

In a separate bowl, whisk together the dry ingredients: the flour, sugar, baking powder, baking soda, and salt. This ensures every component is evenly distributed throughout the batter. Gradually add the dry ingredients to the wet ingredients, folding gently with a spatula just until the last streaks of flour disappear. Overmixing is the enemy of a tender cake, so a light hand is key.

Divide the beautiful, fragrant batter evenly between your prepared pans. Slide them into the preheated oven. If you’re using three 8-inch pans, they’ll need about 20-26 minutes. For two 9-inch pans, plan for 30-36 minutes. You’ll know they’re done when the tops are springy to the touch and a toothpick inserted into the center comes out clean.

While the cakes are cooling completely on a wire rack—this is crucial, as frosting a warm cake is a recipe for disaster—let’s make the frosting. In a large bowl, beat the softened butter and cream cheese together for a good 4-5 minutes. You want it to be incredibly light, pale, and fluffy. Gradually add the powdered sugar, lime juice, and zest, beating until it’s perfectly smooth and spreadable. Pop the frosting into the refrigerator to chill for about 20 minutes; this will make it easier to work with.

Once your cakes are completely cool, it’s time for the grand assembly. Place one layer on your cake stand. Spread a generous amount of frosting over the top. Carefully place the second layer on top, then frost the top and sides of the entire cake, creating beautiful swoops and swirls. Garnish with thin slices of fresh lime for a final touch of elegance.

You Must Know: Key Tips for Success

Room Temperature is King: Ensure your eggs, milk, butter, and cream cheese are all at room temperature before you start. This allows for better emulsification and a smoother, fluffier batter and frosting.
Zest Before You Juice: It is infinitely easier to zest a whole lime than a slippery, juiced one.
Don’t Overmix the Batter: Once you add the flour, mix only until combined. Overworking the gluten will lead to a tough, dense cake.
Cool Completely: Patience is a virtue here. Frosting a warm cake will cause the frosting to melt and slide right off.

Serving It Right

This Key Lime Cake is a star on its own, but a few accompaniments can elevate it further. Serve a slice with a cup of strong, black coffee to balance the sweetness. For a dessert wine pairing, a slightly sweet Moscato or a Riesling would be lovely. For a truly decadent experience, a dollop of lightly sweetened whipped cream on the side is pure heaven.

Make It Different: Customize Your Cake

Coconut Twist: Add 1 cup of toasted coconut to the frosting or sprinkle it on the outside of the cake for a tropical twist.
Graham Cracker Crunch: Press finely ground graham crackers mixed with a little melted butter into the frosting on the sides of the cake for a “Key Lime Pie” effect.
Gluten-Free: Substitute a 1:1 gluten-free flour blend for the all-purpose flour.
A Little Less Sweet: You can reduce the sugar in the cake by 1/4 cup if you prefer a more pronounced tartness.

Storing Your Masterpiece

Store the frosted cake in an airtight container in the refrigerator for up to 5 days. Due to the cream cheese frosting, it should not be left at room temperature for more than 2 hours. You can also freeze the unfrosted cake layers tightly wrapped in plastic wrap and foil for up to 3 months. Thaw overnight in the refrigerator before frosting and serving.

Frequently Asked Questions

1. Can I use regular Persian limes instead of Key limes?
Absolutely. While Key limes are traditional, regular limes are more readily available and work beautifully in this recipe. Their flavor is very similar and still delivers that fantastic citrus punch.

2. My frosting is too soft. What happened?
This usually occurs if the butter or cream cheese was too warm. Pop the entire bowl of frosting into the refrigerator for 20-30 minutes to firm up, then beat it again before using.

3. Can I make this into cupcakes?
Yes! Line a muffin tin with cupcake liners and fill them 2/3 full. Bake at 350°F (175°C) for 18-22 minutes, or until a toothpick comes out clean. This should make about 24 cupcakes.

4. Why did my cake sink in the middle?
This can be caused by a few things: underbaking, opening the oven door too early, or using expired baking powder or soda. Make sure your leaveners are fresh and test for doneness with a toothpick.

5. How can I tell when my cake is perfectly done?
The edges of the cake will just be pulling away from the pan, the top will be springy to the touch, and most importantly, a toothpick inserted into the very center of the cake will come out clean or with a few moist crumbs attached.

Key Lime Cake Recipe

Prep time: 30 minutes
Cook time: 30 minutes
Total time: 1 hour (plus cooling time)
Servings: 12
Category: Dessert
Difficulty: Intermediate
Cuisine: American
Yield: One 2-layer 9-inch cake or 3-layer 8-inch cake

Ingredients

Key Lime Cake:

1 cup canola or olive oil
3 large eggs, room temperature
1 1/3 cups whole milk, room temperature
2 tablespoons fresh lime zest
1 tablespoon fresh lime juice
2 cups granulated sugar
2 cups all-purpose flour
1 teaspoon baking powder
1/2 teaspoon baking soda
1 teaspoon salt

Lime Cream Cheese Frosting:

1/2 cup unsalted butter, softened
8 ounces cream cheese, softened
4 – 4 1/2 cups powdered sugar
1 tablespoon fresh lime juice
1/2 teaspoon fresh lime zest
Fresh limes, sliced for garnish

Instructions

Preheat oven to 325°F (165°C). Grease and line with parchment paper two 9-inch or three 8-inch round cake pans.
In a large bowl, whisk together the oil, eggs, milk, lime zest, and lime juice until smooth and well-combined.
In a separate bowl, whisk together the sugar, flour, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, folding gently with a spatula until just combined. Do not overmix.
Divide the batter evenly between the prepared pans.
Bake: For three 8-inch pans, bake for 20-26 minutes. For two 9-inch pans, bake for 30-36 minutes. The cake is done when a toothpick inserted into the center comes out clean.
Cool the cakes in their pans for 10 minutes, then turn them out onto a wire rack to cool completely.
For the Frosting: In a large bowl, beat the softened butter and cream cheese together for 4-5 minutes, until light and fluffy. Gradually add the powdered sugar, lime juice, and zest, and beat until smooth and spreadable. Chill for 20 minutes if too soft.
Once cakes are completely cool, frost and assemble the layers. Garnish with fresh lime slices.

Notes

For accurate baking, use an oven thermometer.
Ensure all ingredients for the frosting are at room temperature to avoid lumps.