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Easy Key Lime Cake is bursting with fresh lime flavor & topped with whipped cream. A yummy twist on a key lime pie!

Citrus desserts are a must in the summertime, and this Key Lime Cake (inspired by Key Lime Pie), is a favorite. We also love Lemon Bundt Cake, and Lime Sheet Cake when we need a citrus fix!

Key Lime Cake with a bite missing served on a white plate.

a cake version of your favorite pie

We all know about Key Lime Pie, but this Key Lime Cake will give your favorite pie recipe some stiff competition.

The cake itself is super moist and filled with fresh lime flavor. Then it gets soaked in a simple lime syrup, and topped with Whipped Cream and lime zest.

What’s even better is that it’s a shortcut recipe that’s crazy easy to make because the recipe starts with cake mix. Then the lime flavor is fresh and tangy (but never sour) because we’re using fresh limes.

I know a lot of key lime cake recipes use jello for the lime flavor – but I wanted to make a key lime cake without gelatin in it. Spoiler alert – if you don’t have key limes on hand, you can also use regular limes.

How to Make Key Lime Cake

KEY LIME CAKE

PREP. Preheat the oven to 350°F (or 325°F if using a glass pan). Grease and flour the bottom and sides of a 9×13 inch pan. 

WHISK. Add the cake mix, eggs, sour cream, 1/2 c oil, lime juice and lime zest to a large mixing bowl. Beat with an electric mixer on medium speed until smooth.

BAKE. Pour the batter into the prepared pan and bake for 27-32 minutes or until an inserted toothpick comes out clean and if you give the pan a gentle nudge the cake doesn’t wobble in the middle.

COOL. Remove from the oven and allow to cool.

LIME SYRUP

HEAT. In a small saucepan over low heat add the lime juice and sugar. Heat until the sugar dissolves while gently stirring.

BRUSH. When the cake is out of the oven, take a small pastry brush or a spoon and brush/drizzle the syrup over top.

TOPPING

TOP. Spread the whipped topping over top of the cooled cake. Then sprinkle with lime zest.

SERVE. Cut into slices and serve. 

Other topping ideas:

  • Use whipped topping, or homemade whipped cream. Then decorate with a little lime zest.
  • If whipped cream is not your favorite cake topping, try cream cheese frosting. This would give it a sweeter and richer taste, but you could still add lime zest on top to bring in the citrus flavor.
  • Another topping idea is to add a dusting of powdered sugar to the top of the cake and then grate lime zest over the top.
Overhead shot of Key Lime Cake Recipe in a glass baking dish.

Ingredient tips

Cake mix. Use vanilla, white or yellow cake mix, or for even more citrus flavor use lemon cake mix. Make sure not to use angel food cake mix.

Ingredients. Instead of the ingredients listed on the box – we’re using 1/2 oil, 3/4 sour cream, 3 eggs, 1/3 cup fresh lime juice and 2 tablespoons lime zest. The sour cream makes the cake extra moist and using 3 eggs ensures that it’s really tender.

Limes. 6-7 key limes should provide enough juice for the recipe since each lime gives 2-3 teaspoons.

Lime syrup. After the cake is baked, we brush a simple key lime syrup made from sugar and lime juice. If you prefer a more mild lime flavor, feel free to skip this step.

Green food coloring. If you would like to make the cake green like key limes, you can add a drop or two of food coloring. If you are worried about changing the taste or texture of the batter I would suggest gel food coloring because it requires very little to make the color appear.

Key limes are known for being grown in the Florida Keys, hence their name, but they grow all over Florida, in CA and in Mexico. Key limes are typically smaller and more yellow than regular limes. Key limes are also more tart which makes their flavor shine through the sweetness of many desserts. Fresh squeezed key lime juice can be stored in the fridge for 3-5 days or in the freezer for 6 months.

Slice of Key Lime Pie Cake on a white plate.

Make a layered circle cake

Make a Key Lime layered cake by using two 9-inch cake pans.

  • Line each cake pan with a circular piece of parchment paper. Once you have mixed the cake batter, pour it evenly into both pans.
  • Bake at 350°for 22-25 minutes or until a toothpick inserted in the center comes out clean.
  • Allow the cakes to cool a bit in the pan before placing them on wire racks to cool all the way.
  • Add whipped cream between the cake layers. Top with whipped cream.

storing info

STORE the cake, unfrosted on the counter, in an airtight container for 2-3 days. Once the whipped cream has been added to the cake it must be stored in the fridge.

FREEZE. Wrap it tightly and store it in the freezer for up to 6 months.

If you love key lime, try these other favorites:

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Super easy key lime cake is bursting with fresh lime flavor and topped with whipped cream. It's a delicious summer cake recipe, and if you love key lime pie - then definitely give this recipe a try. 
5 from 44 votes

Key Lime Cake Recipe

By: Lil’ Luna
Easy Key Lime Cake is bursting with fresh lime flavor & topped with whipped cream. A yummy twist on a key lime pie!
Servings: 18 slices
Prep: 30 minutes
Cook: 30 minutes
Cooling: 30 minutes
Total: 1 hour 30 minutes

Ingredients 

Key Lime Cake

  • 1 box cake mix , vanilla, yellow or white
  • 1/2 cup vegetable oil
  • 3 large eggs
  • 3/4 cup sour cream
  • 2 tablespoons lime zest
  • 1/3 cup freshly squeezed lime juice

Key Lime Syrup

  • 3 tablespoons lime juice
  • 3 tablespoons sugar

Topping

  • 2 cups whipped topping , or whipped cream
  • 1 tablespoon lime zest
Save This Recipe!
Just enter your email and get it sent to your inbox! Plus you’ll get new recipes from us every week!

Instructions 

Key Lime Cake

  • Preheat the oven to 350F degrees (or 325F degrees if using a glass pan). Grease and flour the bottom and sides of a 9×13 inch pan. 
  • Add the cake mix, eggs, sour cream, 1/2 c oil, lime juice and lime zest to a large bowl.
  • Beat with an electric mixer until smooth.
  • Pour the batter into the prepared pan and bake for 27-32 minutes or until an inserted toothpick comes out clean and if you give the pan a gentle nudge the cake doesn’t wobble in the middle.
  • Remove from the oven and allow to cool.

Lime Syrup

  • In a small saucepan over low heat add the lime juice and sugar. Heat until the sugar dissolves while gently stirring.
  • When the cake is out of the oven, take a small pastry brush or a spoon and brush/drizzle the syrup over top.

Topping

  • Spread the whipped topping over top of the cooled cake. Then sprinkle with lime zest.
  • Cut into slices and serve. 

Notes

*If making the cake ahead of time, make the cake the night before and drizzle with the lime syrup. Cover tightly and leave at room temperature over night.  Add the whipped topping before serving.
**Once the cake has been decorated with whipped topping or whipped cream, cover and store in the fridge. 

Nutrition

Serving: 18g, Calories: 59kcal, Carbohydrates: 5g, Protein: 2g, Fat: 4g, Saturated Fat: 2g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 1g, Trans Fat: 1g, Cholesterol: 37mg, Sodium: 21mg, Potassium: 41mg, Fiber: 1g, Sugar: 4g, Vitamin A: 115IU, Vitamin C: 2mg, Calcium: 22mg, Iron: 1mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Additional Info

Course: Dessert
Cuisine: American
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About Fiona

My name's Fiona and I love to bake and blog. I share homemade, from scratch, classic recipes for desserts & sweet treats including cakes, cupcakes, cookies and more.

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5 from 44 votes (28 ratings without comment)

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Recipe Rating




35 Comments

  1. Alexis says:

    Will the recipe make two 8 or 9 inch layers

    1. Lil'Luna Team says:

      This recipe is for a 9×13 pan, but you could also bake in two 9 inch round cake pans and layer.

  2. Estenoz Marisela says:

    5 stars
    Guests loved the cake with the modifications posted before. I brushed half of the lime syrup on the bottom of the cake and left it overnight before turning it over. In my frig was about 2/3 cream cheese frosting so I added it to the leftover lime syrup, warmed it up and poured it over the Bundt cake once slightly cooked. Even today those guests expressed how delicious the cake was-it’s definitely a keeper.

  3. Deborah says:

    What do you think about adding lime gelatin to the batter!

    1. Estenoz Marisela says:

      5 stars
      Just took it out of the oven since I’m having company tomorrow but added an extra egg and a large lime jello to this recipe using white cake mix. It took exactly 36 minutes to bake and looks beautiful. I will give an update after we have tasted it; I’m excited!!!!!

    2. Estenoz Marisela says:

      Guests loved the cake with the modifications posted before. I brushed half of the lime syrup on the bottom of the cake and left it overnight before turning it over. In my frig was about 2/3 cream cheese frosting so I added it to the leftover lime syrup, warmed it up and poured it over the Bundt cake once slightly cooked. Even today those guests expressed how delicious the cake was-it’s definitely a keeper.

  4. Diana says:

    5 stars
    I used white cake mix, and it was so easy to make and the flavor was amazing! Thank you for the great recipe!

  5. Agnes says:

    Light and delicious! Love citrus flavored dessert.

  6. wilhelmina says:

    5 stars
    This cake is the perfect summer cook out dessert! It’s beyond delicous and makes it easy to feed a crowd!

  7. Jeanette W says:

    5 stars
    Thank you for this! Exactly what I was looking for. I’m using it to make key lime cupcakes with the mini key limes . The only difference is I made some Italian Meringue Buttercream-coconut flavored icing to swirl on top. Beach/Tropical theme birthday.

    1. LilLunaTeam says:

      What a fun treat to make for a tropical themed birthday! The coconut flavored icing sounds heavenly! Thanks for sharing what you do!

  8. Kristi says:

    5 stars
    The lime syrup makes the cake moist and delicious. The simple cream topping was a perfect pair to the cakes flavor.

  9. Olivia says:

    5 stars
    A quick cool dessert with a hint of lime. Very refreshing.

  10. Natalie says:

    5 stars
    We love key lime, just as much as we like lemon. I love mixing it up & alternate between the two cakes. It’s nice & fluffy!