Key Lime Pie Cake has three soft layers of lime cake with tangy lime curd, a buttery graham cracker crumble and luscious honey lime cream cheese frosting. This easy recipe is bright, fresh and perfect for all summer occasions!
I made this recipe with sunny days and citrus lovers in mind! Since limes are in season in summer, it’s extra fresh.
This cake’s a fun take on key lime pie. Each bite is tangy, creamy, and full of bright lime flavor like these lemon and lime bars.
For more delicious citrus desserts, try my Lemon Blackberry Cake and my Lime Drizzle Cake.
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Why We Love This Recipe
- Moist cake layers are packed with lime flavor just like my recipe for key lime cookies!
- Homemade lime curd adds tangy key lime pie flavor. It’s luscious and as super easy just like my quick lemon curd recipe.
- Buttery graham cracker crumble brings in the pie crust vibe with a hint of crunch and toastiness.
- Honey lime cream cheese frosting is creamy, zesty and sweet.
- It’s a great make-ahead dessert! Prep the cake layers, frosting, lime curd, and graham cracker crumble in advance—then just assemble when you’re ready to serve.
Ingredients
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Ingredients for the optional components (the lime curd and graham cracker crumble) are not pictured above. Please see recipe card for full list of ingredients and their measurements.
Below are useful notes about some of the ingredients.
- All-purpose flour-When you measure the flour, spoon your flour into your measuring cup then level it off with the back of a knife.
- Unsalted butter-We’re using room temperature unsalted butter for the cake, frosting and lime curd. If you’re making the graham cracker crumble, use melted or browned butter.
- Oil– Use canola or vegetable.
- Limes- Use key limes or regular limes. We are using both the zest and juice in this recipe.
- Milk and sour cream- Use whole, room temperature milk and sour cream for the cake batter.
- Eggs- You’ll need large, room temperature eggs for the cake and curd.
- Cream cheese– Use full fat, room temperature cream cheese to make the frosting. Make sure you have brick style, not tub style cream cheese.
- Honey (optional)- I love adding a touch of honey to the cream cheese frosting. The sweetness and hint of floral flavor are delicious with the tangy cream cheese and lime. If you don’t have honey, you can leave it out.
- Graham crackers (optional)– For the crumble filling. You’ll need about 8 full sheets or 1 cup of crumbs.
Substitutions & Variations
- Instead of limes, use lemons or a combination of lemons and limes!
- Leave out the lime curd if you prefer. You could also swap in homemade or storebought lemon curd.
- Instead of drizzling lime curd on top, spread some on top of the frosted cake or serve some alongside the cake. People can dollop it on their slices!
- To make this cake extra decadent, top it with toasted meringue. Use the Swiss meringue recipe from my lemon meringue cheesecake, plop it on top of the cake and toast it with a kitchen torch!
How to Make Key Lime Cake
Quick Video Recap
Instructions
Step 1: (See photo 1 above). Rub the lime zest into the sugar with your fingertips. Beat the butter, lime zest, and sugar til light and fluffy. Add the oil. Beat for an additional minute. Add the eggs one at a time.
Step 2: (See photo 2 above). Add the vanilla then add the sour cream. Mix in half the dry ingredients on low speed til just incorporated. Beat in the milk followed by the rest of the dry ingredients.
Step 3: (See photo 3 above). Pour cake batter evenly among the three pans. Bake for 24-29 minutes
Step 4: (See photo 4 above).Make the optional lime curd. See my lemon curd recipe for step by step curd photos. Allow it to chill completely.
Step 5: (See photo 5 above). Make the optional graham cracker crumble. Stir together the graham cracker crumbs, melted butter or brown butter, brown sugar and salt. Spread on a baking sheet. Bake at 350 for 8-10 minutes, stirring once.
Step 6: (See photo 6 above). Beat the butter and the cream cheese with a mixer until combined. With the mixer to low and add the powdered sugar, lime zest, vanilla extract and salt. Beat 2-3 minutes or until light and fluffy.
Step 7: (See photo 7 above). Pipe a border of frosting around the edge of the first layer. Spread about 1/3 cup of lime curd on top. Repeat with the next cake layer. Next add the top layer bottom side up. Set the assembled cake in the fridge for 30–60 minutes to help it set.
Step 8: (See photo 8 above) Once chilled, add a thin crumb coat then chill again for 20–30 minutes before adding the final layer of frosting. Decorate the cake as you like!
EQUIPMENT
Below is a list of some equipment that is useful for making this cake.
- 3 8-inch round cake pans
- Parchment paper-I prefer buttering my cake pans and lining them with a round of parchment paper.
- A microplane- I love using a microplane to zest my limes.
- A serrated knife-to trim the tops of the layers
- Piping bags– for piping frosting
- Ateco 808 tip– for piping borders of frosting on two of the layers. Alternatively, use a zip lock with the end snipped off.
- Wilton 1M tip- for piping decorative frosting on top of cake. Alternatively, leave out the decorations or use your favorite piping tip!
- A plastic squeeze bottle-for drizzling the lemon curd on top. You could also use a teaspoon to drizzle the lemon curd on top.
Recipe FAQs
Key limes are smaller, more aromatic, and have a tangier, more floral flavor than regular (Persian) limes. They’re traditional in key lime desserts, but regular limes work as a substitute if key limes aren’t available.
Yes! While key limes have a more intense, tangy flavor, regular limes (like Persian limes) work well as a substitute in this recipe. The cake will still be bright, citrusy, and delicious.
On average, one medium lime yields about 2 tablespoons of juice and 1 to 1½ teaspoons of zest. Key limes are much smaller, so you’ll need about 4–6 key limes to get the same amount of juice.
Store leftover frosted cake in an airtight container in the refrigerator for up to 5 days. Unfrosted cake layers can be frozen for up to 2 months. Thaw before decorating.
Expert Tips
- Avoid the white part when zesting the limes. The white rind can be bitter. You want only the outer green zest.
- To get the most juice, roll each lime firmly on the counter with your palm or microwave it for 10–15 seconds.
- If you’re going to pipe frosting on top, chill frosting for about 20 minutes. This helps the frosting hold its shape when it’s piped.
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Key Lime Pie Cake
Equipment
- Microplane
Ingredients
Lime Cake
- 3 cups (375 g) all-purpose flour
- 3¾ teaspoons (3¾ teaspoons) baking powder
- 1 teaspoon (1 teaspoon ) salt
- 1¾ cups (350 g) granulated sugar
- 4 large (4 large) eggs room temperature
- ½ cup (113.5 g) unsalted butter room temperature
- ½ cup (118.29 ml) oil canola or vegetable
- 2 ½ teaspoons (2 ½ teaspoons ) vanilla extract
- 2 tablespoons (2 tablespoons) lime zest fresh key lime zest or zest from regular limes
- 1¼ cups (295.74 ml) whole milk room temperature
- ¾ cup (172.5 g) full fat sour cream room temperature
Lime Curd (optional)
- 2 tablespoons (2 tablespoons) lime zest key lime zest or zest from regular limes
- ⅔ cups (133.33 g) granulated sugar
- 3 large (3 large) eggs
- 1 pinch (1 pinch) salt
- ½ cup (118.29 ml) lime juice key lime juice or juice from regular limes
- 4 tablespoons (56 g) unsalted butter room temperature
Graham Cracker Crumble (optional)
- 1 cup (84 g) graham cracker crumbs about 8 full graham crackers
- ¼ cup (56.75 g) butter melted
- 2 tablespoons (24 g) brown sugar light or dark, packed
- 1 pinch (1 pinch) salt
Honey Lime Cream Cheese Frosting
- 1 cup (227 g) unsalted butter room temperature
- 8 ounces (226.8 g) full fat cream cheese room temperature
- 1½ teaspoons (1½ teaspoons) vanilla extract
- 3 teaspoons (3 teaspoons) lime zest key lime zest or zest from regular limes
- 2 teaspoons (9.86 ml) lime juice key lime juice or juice from regular limes
- 2 teaspoons (2 teaspoons) honey optional
- 5 cups (600 g) powdered sugar sifted, add up to 6 cups, to taste
- ¼ teaspoon (1.5 g) salt
Instructions
Lime Cake
- Preheat oven to 350 F. Grease 3 8″ cake pans with butter. Line with parchment paper. Grease parchment paper with butter.
- In a medium bowl, whisk to combine the flour, baking powder, and salt. Set aside.
- In a standing mixer fitted with the paddle attachment or in a large bowl using a hand held mixer cream the butter, lime zest, and sugar for 2 minutes
- Add the oil and beat for another minute.
- With the mixer on medium speed, add the eggs one at a time til incorporated.
- Add the vanilla extract followed by the sour cream. Beat til just incorporated.
- Add in half the dry ingredients. Mix on low speed til just incorporated. Beat in the milk followed by the other half of the dry ingredients.
- Pour cake batter evenly among the three pans. Bake for 24-29 minutes or until a tooth pick comes out clean when inserted into the middle of the cake. Place cake pans on a wire rack and allow to cool completely before frosting.
Lime Curd (optional)
- Cut the butter into four pieces. Place the butter in a medium heat proof glass mixing bowl. Place a large fine sesh sieve over the bowl. Set aside.
- Add the sugar and lime zest to a medium pot. Use your fingertips to rub the zest into the sugar.
- Pour the lime juice, pinch of salt and eggs into the sugar and whisk to combine. Try to break up the egg whites while you whisk. Set pot over low heat.
- Stir constantly with a silicone whisk while the curd cooks and until the curd thickens. Cook for about 10-13 minutes or until the curd registers 160 to 170 F on an instant read thermometer. You can also check for doneness using the spoon method. Dip a wooden spoon into the curd and run your finger across the back of the spoon to make a line. If the line stays clear, the curd is ready.
- Remove pot from heat. Pour the curd through the sieve into the butter. Use a spatula to help press the curd throught the sieve. Set sieve aside then stir curd til the butter has melted completely. Pour the curd into an airtight container. Allow to cool til room temperature before covering the container. Set in the fridge to chill til you're ready to use it.
Graham Cracker Crumble (optional)
- Preheat oven to 350 ℉.
- In a medium mixing bowl, stir to combine the graham cracker crumbs and salt. Stir in the melted butter til crumbs are all well coated.
- Spread crumbs out evenly on a baking sheet. Bake for 8-10 minutes. Carefully stir mixture once halfway through baking.
- Allow to cool completely.
Honey Lime Cream Cheese Frosting
- In the bowl of an electric mixer fitted with the paddle attachment or in a large mixing bowl using a handheld electric mixer, beat the cream cheese on medium for one minute.
- Add the butter and honey. Beat for 2-3 minutes until combined and fluffy.
- Turn the mixer to low and add the sifted powdered sugar one cup at a time. Add the lime zest, lime juice, vanilla extract and salt. Turn mixer to medium high and beat for an additional 2-3 minutes until light and fluffy.
Assembling the Cake
- Place the first layer on your cake stand or turntable.
- Pipe a ½ inch border of frosting around the edge of the cake. (Use a piping bag fitted with an open tip such as Ateco 808 or a large zip lock bag with a corner snipped off). This will keep the curd filling secure. Spread about ⅓ cup of lime curd til reaches the frosting around the edge. Evenly sprinkle about 3-4 tablespoons of the graham cracker crumble on top of the curd. Place the second layer of cake evenly on top.
- Repeat with the same decorating process with the frosting, curd and graham cracker crumble. Place the third layer upside down so that the bottom of the layer is on top of the cake. This gives will make sure the top is even and flat.
- Set the assembled cake in the fridge for 30–60 minutes to help it set. Once chilled, add a thin crumb coat (a light layer of frosting to catch crumbs), then chill again for 20–30 minutes before adding the final layer of frosting. This makes frosting smoother and keeps everything neat and stable.
- Decorate the cake as you like! Top with lime slices or pipe some extra frosting on top or keep it simple and spread a little lime curd on top and sprinkle edge of top with graham cracker crumble. You can also scoop some extra graham cracker crumble with your hand and press it into the sides right after frosting the cake.
- Optional: Pour some of the lime curd into a squeeze bottle or use a teaspoon to drizzle lime curd along the edge of the cake. Add a little extra lime juice to the curd if you need to thin it out.
Video
Notes
Nutrition
Please note that nutritional values are created by an online calculator and should only be used as an estimate.
Joanne
Joanne
This cake is delicious and very moist.
Just the perfect sweetness.
Natalie
Hi Joanne, Thank you for giving this lime cake a try! I’m so happy you enjoyed it. Xo Natalie
Paige
Delicious, made without curd
Natalie
Hi Paige, Thanks so much for making this cake. So happy you enjoyed it!