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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. 
4.94 from 45 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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4.94 from 45 votes (28 ratings without comment)

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Recipe Rating




36 Comments

  1. Lisalia says:

    5 stars
    The perfect flavor of citrus in such a yummy textured cake. Thank you for always having the BEST recipes. This is a new family favorite!

  2. Allyssa says:

    5 stars
    So easy to make and tasted really amazing! Thank you so much for this key lime cake recipe, will surely have this again! Fam really loves it! Well done!

  3. Amy L Huntley says:

    5 stars
    I am a huge fan of anything Key Lime Pie! This cake did not disappoint! So moist and full of that delicious key lime flavor.

  4. Joy says:

    5 stars
    We have made this a few times this summer. It’s always so refreshing & can feed a crowd.

  5. Carol Bledsoe says:

    Can you do this in bundt pan?

    1. LilLunaTeam says:

      Yes you sure can! Just make sure you don’t overfill the bundt pan – leave at least 1/2 inch of empty space from the top. Also – you will need to adjust your cooking time. Bundt cakes typically take about 40-45 minutes to bake so I would check it at 40 minutes by inserting a toothpick into the center to see if it comes out clean. If it does not come out clean then bake it for 5-10 more minutes and check again. Hope this helps!

  6. Katie says:

    In the list of ingredients for key lime cake you dont have oil- in instructions you say add 1/2 cup oil.
    I caught it- but didnt add. We’ll see how it turns out. ?

    1. Kristyn Merkley says:

      Yes, sorry..had it in the instructions, but forgot the ingredient list, so thank you for catching that!! Uh, oh..hope it’s ok 🙂

  7. Erika Ann says:

    5 stars
    This looks absolutely delicious! A bit difficult for me to make as a beginner but I think its worth a try!

    1. Kristyn Merkley says:

      Totally worth a try 🙂 You can do it! You will love it!

      1. ava says:

        5 stars
        yes it was so good

  8. Divya says:

    I made this cake and loved the flavor. However, the cake itself was very dry. Any ideas why? Is it because there is no oil?

    Thank you

    1. Kristyn Merkley says:

      The lime juice makes up the liquid. I am not sure?? It hasn’t been too dry for us, so really I’m not sure what happened. I wish I could be more help. I’m sorry. I appreciate you making it 🙂

    2. Connie says:

      In the intro she says they use 1/2 C. oil, but it’s not included in the ingredients list or directions. That’s probably the problem…

      1. Kristyn Merkley says:

        Yes, sorry..I need to add that. I had it in the paragraph, but forgot it in the ingredients. You add 1/2 cup oil, when mixing the ingredients in step 2. Sorry about that 🙂

      2. Elaine Nesbitt says:

        Does the cake need to be completely cooled before you put the lime syrup on?

      3. Lil'Luna Team says:

        I mostly cool the cake before putting the lime syrup on. You’ll want to for sure make sure the cake is cooled before putting the whipped topping o too.

  9. Sabrina says:

    5 stars
    love key lime flavors, cake too, so thank you and thank you for these other links too!

    1. Kristyn Merkley says:

      You are so welcome!! Thank you for stopping by!

  10. Divya says:

    Which flavor cake mix did you use?
    I am definetely making this soon!
    Love your blog!

    1. Kristyn Merkley says:

      You could do either vanilla, white, or yellow cake mix. I think mine was yellow cake mix. Any of those taste great 🙂 Hope you try it soon!