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Key Lime Pie Cake

April 17, 2012

I made you a cake!

Just kidding. I made my dad a cake. He had another birthday – which he insists on doing every year, like clockwork – so I decided to make him a cake. I’ve talked about how much he likes key lime pie before. This year I threw in a twist – I made him Key Lime Pie Cake.

Key Lime Pie Cake

This whole cake is built around one key component: the key lime curd. It’s just like this quick & easy lemon curd, but it’s made with key lime juice instead. Once done, it tastes just like the silky sweet and mouth puckering filling of a key lime pie. SO good.

All finished, the cake was lovely. My best cake frosting job to date, if I may toot my own horn. It’s made of two layers of light and tender lime-scented white cake, with a thick layer of key lime curd between them, then frosted with a smooth and rich lime Swiss Meringue Buttercream. To finished it off, I toasted some graham cracker crumbs for the outside because we all know it’s not key lime pie without a graham cracker crust.

Key Lime Pie CakeKey Lime Pie Cake

I don’t make full layer cakes like this very often because they’re such a project and there usually aren’t enough people around to eat them. That, and the suspense of waiting until the first slice to see if it tastes good just about kills me. What if it’s awful and I’ve just served it to a whole group of people? Yikes.

Key Lime Pie Cake

That said… I think this cake was a success. It tasted good, it looked good, and everyone who ate it seemed pleased. However, I think there’s a few things I would do differently next time:

– When I put the cake together, I was concerned that the wallop of flavor from the key lime curd could be overpowering and too rich when combined with frosting, so I went a little light on the curd. After tasting the cake myself* and harassing everyone who ate it for their opinions, I think I could have used more curd. It was by far the best and most flavorful part of the cake.

– I only used two layers because I had to travel with the cake and I was afraid more layers would not hold up in transit. Next time If I don’t have to travel with the cake, I’d like to try halving each cake layer to make four layers total. That would make room for more curd too!

– By the time we ate the cake, it was a little dry. I think this was due to 3 things: I was careless with measuring and used a little too much flour; I overbaked the cake layers a bit; and the cake sat uncovered in the fridge for a few days before eating. I’ve used this cake recipe before and it wasn’t dry, so I am sure the recipe is not at fault. Next time, I might baste the cake layers with a lime simple syrup just to ensure it stays moist.

* I was sick with the plague (aka a nasty cold) when I tasted this cake, and as such I could barely taste anything. I’m basing my opinions on what little I could taste and what others said about how it tasted.

Key Lime Pie Cake

Key Lime Pie Cake

Printable Recipe (includes all sub-recipes)
Makes one 9-inch layer cake

This cake has several components, most of which can (and should) be made ahead. Final assembly will ideally take place the same day the cake is served, but the cake can be stored in the fridge for up to 2 days.


Key lime curd
Lime scented white cake
Graham Cracker Crumble
Lime Swiss Meringue Buttercream


Prepare key lime curd according to directions below at least one day (up to 3 days) ahead.

Bake cake layers according to directions below. Cool completely before frosting.

Prepare the Lime Swiss Meringue Buttercream according to directions below.

To assemble, place one cake layer (top side up) on a cake plate or board. Place about 3/4 cup of buttercream in a piping bag with a large round tip. Pipe frosting around top edges of cake to create a border of frosting. Fill in center with 1/2 cup or more of Key Lime Curd. Place other cake layer (top side down) on top.

Spread of thin layer of buttercream over top and sides of cake to form a crumb coat. Refrigerate cake for 30 minutes to 1 hour.

Place 1/4 to 1/2 cup of frosting in a piping bag with a star tip. Spread the remaining frosting evenly over top and sides of the cake. Press Graham Cracker Crumble into sides of cake. Spread about 1/2 cup of Key Lime Curd over top of cake, leaving 1/2-inch border. Pipe stars around top edge border.

Key Lime Curd

Adapted from Gourmet
Makes about 3 cups

I made a large batch of curd not knowing how much I would end up needing for final cake assembly. As pictured and described above, I only needed half of the curd for the cake. However, if you plan to make your cake 4 layers you will probably need the whole batch.

This recipe is very easy, but the key is patience. You must cook the curd on LOW heat very slowly and you must whisk constantly. For reference, my electric stove burners range from 1 to 9. I cooked my curd on 3-4 for 10+ minutes.


1 1/2 cups granulated sugar
zest of 4 limes
1 cup Key Lime juice
4 large eggs
8 tablespoons unsalted butter, cut into tablespoon-sized pieces


Add all ingredients except butter to a saucepan over Low heat. Whisk to combine. Add butter. Continue whisking gently but constantly, heating slowly, until curd thickens and reaches 160°F on an instant read thermometer. Remove from heat.

For the smoothest curd, pour through a fine mesh strainer. Transfer to a storage container. Cover and refrigerate overnight before use. Curd keeps up to 1 week in the fridge.

Lime Scented White Cake

Adapted from Baking: From My Home to Yours by Dorie Greenspan
Makes 2 9-inch cakes


2 1/4 cups cake flour
1 tablespoon baking powder
1/2 teaspoon salt
1 1/4 cups buttermilk
4 large egg whites
1 tablespoon lime juice
1 1/2 cups sugar
zest of 1 lime
1 stick (8 tablespoons) unsalted butter, room temperature
1/2 teaspoon vanilla extract


Preheat oven to 350°F. Spray two 9-inch round cake pans with baking spray.

Whisk together cake flour, baking powder and salt in a small bowl. In a 2-cup measuring cup, first measure out buttermilk, the whisk in egg whites and lime juice.

In the bowl of a stand mixer, beat sugar and zest on low until fragrant, about 2 minutes. Add butter and beat until light and fluffy, about 3 minutes. Beat in vanilla extract. With the mixer on low, add 1/3 of the flour mixture, followed by 1/2 buttermilk mixture. Continue alternating dry and wet ingredients (ending with dry ingredients), beating just to incorporate each new addition. Once all ingredients are added, beat on medium speed for 2 minutes to aerate the batter.

Divide batter evenly between pans. Bake at 350°F for 30-35 minutes, or until toothpick in the center comes out clean. Cool in pans for 5 minutes, then invert cakes onto a cooling rack to cool completely.

Can be made ahead. If making ahead, wrap each layer tightly in plastic wrap and place in a zip top bag. Can be stored at room temperature for a day, or frozen for several weeks.

Graham Cracker Crumble


6 graham crackers
pinch of salt
2 Tablespoons brown sugar
4 Tablespoons unsalted butter, melted


Preheat over to 350°F. Line a baking sheet with a Silpat or parchment paper.

Break graham crackers into quarters and pulse in a food processor until reduced to fine crumbs. Add salt and brown sugar. With processor running, pour in melted butter. Pulse until mixture resembles wet sand.

Dump mixture onto prepared pan and press mixture firmly to form a flat ‘crust’. Bake at 350°F for 6 minutes. Remove from oven and crumble into pieces with a fork. Return to oven and bake 2 more minutes. Cool completely. Can be made ahead and stored in an air-tight zip top bag until needed.

Lime Swiss Meringue Buttercream

Makes about 5 cups, or enough to frost a 9-inch layer cake

If you end up making this a 4-layer cake, you may want to make an extra bit of frosting. As is, it was enough for me to frost a 2-layer cake.


6 large fresh egg whites
1 1/4 cup granulated sugar
2 1/2 sticks unsalted butter, room temperature, cut into 1-Tablespoon cubes
1 teaspoons pure vanilla extract
1 tablespoon key lime juice
lime zest
Pinch of salt


Fill medium saucepan with about an inch of water and bring to a simmer. Add egg whites and sugar to the metal bowl of a stand mixer. Set bowl over simmering water and whisk constantly until sugar has dissolved and mixture reads 140°F on an instant read thermometer.

Attach bowl to stand mixer and using the whisk attachment, beat on medium speed until a glossy white meringue with stiff peaks forms and the bowl no longer feels warm to the touch (about 10-15 minutes). Switch to the paddle attachment. Beating on medium-low speed, add butter one piece at a time, letting each piece incorporate before adding the next. Once all butter is incorporated, scrape down sides of the bowl with a spatula. Continue beating for 10-15 minutes until smooth.

Once smooth, add vanilla, lime juice, salt and zest. Beat until smooth.

(If at any point your buttercream looks curdled or soupy – don’t panic and for pete’s sake don’t throw it out! If it looks curdled, just keep beating. It will come together, I promise. If you’ve been beating it for 15 minutes and it’s still soupy, pop the whole bowl in the fridge for 10 minutes, then continue beating. Repeat as much as necessary until you get a smooth buttercream.)

  1. Amy permalink
    April 17, 2012 10:30 pm

    It’s certainly a beautiful cake. Well done!

  2. April 18, 2012 3:44 am

    SO beautiful!

  3. April 18, 2012 4:02 am

    I can just imagine the taste – can’t get key limes here in the south of France so will have to use regular limes but I’m sure it’ll be delicious! Am wondering if you have a metric conversion for the cake recipe, I find that weighing rather than measuring gives more consistent results with baking, especially with sponge cakes. Am looking forward to your next recipe!

    • The Craving Chronicles permalink*
      April 18, 2012 3:09 pm

      Regular limes should work just fine if you can’t get key limes. I used a mix of key lime juice and regular lime zest for my cake. I wish I had metric conversions for you! The original cake recipe does not have them, which I’m sure would have prevented me from using too much flour in my cake. If I can find the weight for the flour I will add it to the recipe for future use.

  4. April 18, 2012 4:11 am

    That is truly one of the best looking cakes I’ve ever seen – it must taste absolutely fantastic too.

  5. Jen permalink
    April 18, 2012 10:08 am

    There’s no way this could NOT taste fantastic! I totally love key lime pie. Making it into a cake was a great idea!

  6. April 18, 2012 2:50 pm

    Hope you are feeling better!

    • The Craving Chronicles permalink*
      April 18, 2012 3:08 pm

      I am, thanks Tracy :) It was a rough couple of days having no sense of taste! haha

  7. April 18, 2012 3:29 pm

    Wow!! This is a stunning cake!! Love it!

  8. April 18, 2012 4:11 pm

    Such a pretty cake! I love that you thought to put the graham cracker crumbs on the outside. I bet it would be good with any kind of citrus.

    Regarding your comment above about flour, these ingredient weight charts are super helpful. I have the modern domestic one printed out so I can consult it when I’m baking or converting a recipe:

  9. April 18, 2012 5:04 pm

    Yum! This looks absolutely delicious! Beautiful photos.

  10. April 18, 2012 8:19 pm

    Gorgeous cake! My husband adores key lime. I need to make this for him!

  11. April 18, 2012 8:50 pm

    i love this idea for a cake! I’m a huge fan of key lime pie myself, why not make it into a cake?! yumm :)

  12. April 18, 2012 8:58 pm

    This sounds like a perfect Summer cake, like exactly what I need for my birthday :) My only problem is that by the middle of July I tend to not want to bake anything, but this looks worth it!

  13. April 18, 2012 9:00 pm

    now, if I could only spell my own name, all would be right in the world lol. Daniela. not Daniwla :D

  14. April 19, 2012 6:50 am

    I LOVE key lime pie, so I think I will extra specially love it in cake form! Bravo! Thanks for sharing, I’m going to make this this weekend haha

  15. April 19, 2012 1:08 pm

    “…harassing everyone who ate it for their opinions…” This made me chuckle, because yeah, I do that, too.

  16. April 30, 2012 11:33 am

    What a fantastic cake! It turned out so beautifully and I bet it’s so delicious. Thanks for sharing!

  17. Francesca permalink
    April 30, 2012 12:23 pm

    What a fantastic and beautiful lookingcake! It turned out lovely and tastey too I am sure. I hope you enjoyed it. I ‘heard’ about you via Two Peas and their Pod – you have a very lovely Blog, thank you

  18. May 24, 2012 10:13 pm

    My wife wants to try this soon! I’m very excited. :)

  19. Julio permalink
    June 14, 2012 8:36 pm

    So I made this last weekend. It took quite the effort! But it was sooooo worth it! I’m not sure if the cake worked out correctly, though. I think the cake stayed a bit flat and it tasted a little flowery. That said when put all together it was phenomenal so I WILL try this again and soon!

  20. June 21, 2012 12:51 am

    This looks so incredibly delicious! I can’t wait to try it this summer.

  21. sandhy2002 permalink
    March 10, 2014 4:09 pm

    Thanks for this! I made it for a friends shower in cupcake form. I used the curd as a filling and rolled each iced cupcake in the graham cracker crumbles. I finished with a thinly sliced piece if line on top. It got really good reviews!

    • The Craving Chronicles permalink*
      March 10, 2014 5:33 pm

      Love hearing that! I had considered making them cupcakes too, but haven’t gotten around to it yet :)

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