I can’t get over how this key lime cake turns out so light, moist, and packed with bright citrus zing. One slice looks innocent, but that tangy lime finish keeps everyone coming back for more.

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I’m honestly obsessed with this key lime cake because it hits that sweet spot between bright, tangy, and soft without feeling heavy. The fresh key lime juice gives every bite a sharp little citrus pop, while sour cream keeps the crumb ridiculously moist and tender.

I love how the flavor tastes bold but still clean, like summer showed up on a plate and brought dessert. And that zingy finish?

So good. But what really gets me is how the cake feels light enough for seconds, yet rich enough to feel special.

Sweet, tart, fluffy. My kind of cake, every time.

Ingredients

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All-purpose flour gives the cake its soft, sturdy crumb without feeling heavy.
Granulated sugar sweetens things up and helps the edges bake golden.
Baking powder adds lift, so you don’t end up with a dense brick.
Fine salt keeps the sweetness in check and makes the lime pop.
Butter brings that rich, bakery-style flavor you’ll definitely notice.
Vegetable oil keeps the cake moist for days, which is always a win.
Eggs hold everything together and add a little richness.
Sour cream or Greek yogurt makes it tender, tangy, and not dry.
Key lime juice brings the bright, tart kick this cake needs.
Lime zest adds fresh citrus flavor without making the cake too sour.
Vanilla softens the tang and rounds out the sweetness nicely.
Milk loosens the batter so the texture stays light.
Cream cheese makes the frosting creamy, tangy, and honestly kind of addictive.
Powdered sugar sweetens the frosting and keeps it smooth, not gritty.
Plus, whipped cream and lime slices make it look cute with zero stress.

Ingredient Quantities

2 cups (240 g) all purpose flour

1 1/2 cups (300 g) granulated sugar

2 1/2 teaspoons baking powder

1/2 teaspoon fine salt

1/2 cup (113 g) unsalted butter, softened

1/4 cup (60 ml) vegetable oil

3 large eggs, room temperature

1 cup (240 g) sour cream or plain Greek yogurt, room temperature

1/3 cup (80 ml) fresh key lime juice (or regular lime juice if unavailable)

2 tablespoons finely grated lime zest (about 2 to 3 limes)

1 teaspoon pure vanilla extract

1/4 cup (60 ml) milk, room temperature (more if needed for batter)

For the frosting or glaze: 8 ounces (225 g) cream cheese, softened

1 1/2 to 2 cups (180 to 240 g) powdered sugar, sifted, adjusted to taste

2 to 3 tablespoons fresh key lime juice for frosting

1 teaspoon lime zest for frosting or garnish

Optional garnish: whipped cream and extra lime slices or zest

How to Make this

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1. Preheat oven to 350°F and grease and flour a 9×13 inch pan or two 8 inch round pans; line bottoms with parchment for easier removal.

2. In a medium bowl whisk together 2 cups all purpose flour, 2 1/2 teaspoons baking powder and 1/2 teaspoon fine salt; set aside.

3. In a large bowl or stand mixer beat 1/2 cup softened unsalted butter with 1 1/2 cups granulated sugar until light and fluffy, then beat in 1/4 cup vegetable oil until incorporated.

4. Add 3 large room temperature eggs one at a time, mixing well after each, then mix in 1 teaspoon pure vanilla extract and 2 tablespoons finely grated lime zest.

5. In a small bowl combine 1 cup room temperature sour cream or plain Greek yogurt with 1/3 cup fresh key lime juice and 1/4 cup milk.

6. With mixer on low speed add the dry ingredients to the butter mixture in three additions, alternating with the sour cream mixture, beginning and ending with the dry ingredients; scrape the bowl and mix just until batter is smooth, add a splash more milk if needed to reach a pourable consistency.

7. Pour batter into prepared pan(s), smooth the top, and bake 25 to 35 minutes for 9×13 or 22 to 28 minutes for 8 inch rounds, until a toothpick inserted in the center comes out clean; cool in the pan 10 minutes then transfer to a wire rack to cool completely.

8. For the frosting beat 8 ounces softened cream cheese until smooth, gradually add 1 1/2 to 2 cups sifted powdered sugar to taste, then beat in 2 to 3 tablespoons fresh key lime juice and 1 teaspoon lime zest until creamy; adjust thickness with more powdered sugar or a little milk if needed.

9. Once cake is completely cool, spread the cream cheese lime frosting over the cake, garnish with additional lime zest, optional whipped cream and lime slices, then chill briefly to set before serving.

Equipment Needed

1. 9×13 inch baking pan or two 8 inch round pans
2. Parchment paper
3. Medium and large mixing bowls
4. Stand mixer or electric hand mixer with paddle attachment
5. Whisk
6. Rubber or silicone spatula
7. Measuring cups and spoons
8. Microplane or fine grater for zesting
9. Toothpick or cake tester
10. Wire cooling rack

FAQ

Can I use regular limes instead of key limes? A: Yes. Use the same quantity of regular lime juice and zest. Key limes are just more aromatic, so the flavor will be slightly different but still bright and tangy.

My batter seems thick. Should it be thinner? A: The batter should be pourable but not runny. Add the milk 1 tablespoon at a time until it reaches a smooth, slightly thick pourable consistency. Do not overthin.

How do I know when the cake is done? A: Bake until a toothpick inserted in the center comes out with a few moist crumbs but not wet batter, and the top springs back lightly when touched.

Can I make the cake ahead or freeze it? A: Yes. The unfrosted cake layers can be wrapped tightly and frozen up to 2 months. Thaw in the fridge overnight before frosting. Frosted cake keeps in the fridge 3 to 4 days.

My frosting is too runny or too thick. How do I fix it? A: If too runny, chill briefly and add more sifted powdered sugar 1 tablespoon at a time. If too thick, whisk in a teaspoon of milk or lime juice at a time until spreadable.

Can I swap the sour cream for Greek yogurt and will it affect the cake? A: Yes. Full fat plain Greek yogurt is an equal substitute and will give the same moisture and tender crumb. Low fat options may produce a slightly less rich cake.

Bake This Easy Key Lime Cake – Sweet, Tangy & Delicious! Recipe Substitutions and Variations

Unsalted butter: substitute with equal amount of melted coconut oil or vegetable oil for a dairy free option; coconut will add a mild coconut flavor.
Eggs: replace each egg with 1 tablespoon ground flaxseed mixed with 3 tablespoons water, let sit 5 minutes to gel; works well for binding in quick cakes.
Key lime juice: use regular fresh lime juice 1 1/1 times the amount, or lemon juice in a pinch for a brighter, less authentic flavor.
Cream cheese (for frosting): swap with mascarpone or full fat Greek yogurt (drained slightly) for a tangy, slightly lighter frosting; adjust powdered sugar for consistency and sweetness.

Pro Tips

1. Make everything room temperature before you start. Eggs, sour cream and cream cheese all blend into a silkier batter and frosting when they are not cold, which helps the cake stay tender and prevents lumps.

2. Zest before you juice. Grate the lime zest first and then squeeze the limes. The zest holds more of the bright oils than the juice, so adding it early to the butter-sugar mix wakes up the batter with real lime aroma.

3. Use a gentle mixing rhythm. Add the dry and wet components in alternating additions and stop mixing as soon as the batter is uniform. Overworking develops gluten and can make the crumb tough. If the batter looks a bit thick, add the milk a tablespoon at a time until it pours slowly off the spoon.

4. Chill the frosted cake briefly before serving and for cleaner slices. The cream cheese frosting firms up when cold, making spreading neater and giving you prettier pieces. Store leftovers tightly covered in the fridge for up to 4 days.

Bake This Easy Key Lime Cake – Sweet, Tangy & Delicious! Recipe

Recipe by Samantha Dalling

0.0 from 0 votes

I can’t get over how this key lime cake turns out so light, moist, and packed with bright citrus zing. One slice looks innocent, but that tangy lime finish keeps everyone coming back for more.

Servings

servings

Calories

568

kcal

Equipment: 1. 9×13 inch baking pan or two 8 inch round pans
2. Parchment paper
3. Medium and large mixing bowls
4. Stand mixer or electric hand mixer with paddle attachment
5. Whisk
6. Rubber or silicone spatula
7. Measuring cups and spoons
8. Microplane or fine grater for zesting
9. Toothpick or cake tester
10. Wire cooling rack

Ingredients

2 cups (240 g) all purpose flour
1 1/2 cups (300 g) granulated sugar
2 1/2 teaspoons baking powder
1/2 teaspoon fine salt
1/2 cup (113 g) unsalted butter, softened
1/4 cup (60 ml) vegetable oil
3 large eggs, room temperature
1 cup (240 g) sour cream or plain Greek yogurt, room temperature
1/3 cup (80 ml) fresh key lime juice (or regular lime juice if unavailable)
2 tablespoons finely grated lime zest (about 2 to 3 limes)
1 teaspoon pure vanilla extract
1/4 cup (60 ml) milk, room temperature (more if needed for batter)
For the frosting or glaze: 8 ounces (225 g) cream cheese, softened
1 1/2 to 2 cups (180 to 240 g) powdered sugar, sifted, adjusted to taste
2 to 3 tablespoons fresh key lime juice for frosting
1 teaspoon lime zest for frosting or garnish
Optional garnish: whipped cream and extra lime slices or zest

Directions

Preheat oven to 350°F and grease and flour a 9×13 inch pan or two 8 inch round pans; line bottoms with parchment for easier removal.
In a medium bowl whisk together 2 cups all purpose flour, 2 1/2 teaspoons baking powder and 1/2 teaspoon fine salt; set aside.
In a large bowl or stand mixer beat 1/2 cup softened unsalted butter with 1 1/2 cups granulated sugar until light and fluffy, then beat in 1/4 cup vegetable oil until incorporated.
Add 3 large room temperature eggs one at a time, mixing well after each, then mix in 1 teaspoon pure vanilla extract and 2 tablespoons finely grated lime zest.
In a small bowl combine 1 cup room temperature sour cream or plain Greek yogurt with 1/3 cup fresh key lime juice and 1/4 cup milk.
With mixer on low speed add the dry ingredients to the butter mixture in three additions, alternating with the sour cream mixture, beginning and ending with the dry ingredients; scrape the bowl and mix just until batter is smooth, add a splash more milk if needed to reach a pourable consistency.
Pour batter into prepared pan(s), smooth the top, and bake 25 to 35 minutes for 9×13 or 22 to 28 minutes for 8 inch rounds, until a toothpick inserted in the center comes out clean; cool in the pan 10 minutes then transfer to a wire rack to cool completely.
For the frosting beat 8 ounces softened cream cheese until smooth, gradually add 1 1/2 to 2 cups sifted powdered sugar to taste, then beat in 2 to 3 tablespoons fresh key lime juice and 1 teaspoon lime zest until creamy; adjust thickness with more powdered sugar or a little milk if needed.
Once cake is completely cool, spread the cream cheese lime frosting over the cake, garnish with additional lime zest, optional whipped cream and lime slices, then chill briefly to set before serving.

Notes

Below you’ll find my best estimate of this recipe’s nutrition facts. Treat the numbers as a guide rather than a rule—great food should nourish both body and spirit. Figures are approximate, and the website owner assumes no liability for any inaccuracies in this recipe.