This Key Lime Pie Cake blends the zesty brightness of key lime pie with the fluffy sweetness of a classic layer cake. Each bite delivers tangy citrus, silky filling, and whipped cream frosting that tastes like summer in dessert form.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
For the Cake:
2 ½ cups all-purpose flour
2 ½ tsp baking powder
½ tsp salt
1 cup unsalted butter, softened
1 ¾ cups granulated sugar
4 large eggs
1 tbsp lime zest (from about 2 limes)
⅓ cup fresh key lime juice (or regular lime juice)
1 tsp vanilla extract
1 cup buttermilk
For the Key Lime Filling:
1 can (14 oz) sweetened condensed milk
4 large egg yolks
½ cup fresh key lime juice
1 tbsp lime zest
For the Frosting:
1 cup heavy cream
⅓ cup powdered sugar
1 tsp vanilla extract
Lime zest or thin lime slices for garnish
Directions
Bake the Cake:
I preheat the oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing and flouring them. In one bowl, I whisk together the flour, baking powder, and salt.
In a separate bowl, I cream the butter and sugar until light and fluffy, then add the eggs one at a time. I stir in the lime zest, juice, and vanilla.
Alternating, I mix in the flour mixture and buttermilk, starting and ending with the flour. Once combined, I divide the batter between the pans and bake for 25–30 minutes until a toothpick inserted comes out clean. Then I let the cakes cool completely.
Make the Key Lime Filling:
In a medium bowl, I whisk the sweetened condensed milk, egg yolks, lime juice, and zest until smooth. I pour the mixture into a saucepan and cook it over low heat, stirring constantly for about 8 minutes, until thickened. I let it cool fully.
Assemble the Cake:
I place one cake layer on a serving plate and spread half of the key lime filling on top. Then I place the second layer and spread the remaining filling over it, or I save some for serving on the side.
Make the Frosting:
I beat the heavy cream, powdered sugar, and vanilla until stiff peaks form. Then I frost the top and sides of the cake.
Garnish:
I finish the cake with lime zest or thin lime slices for a pop of color and citrus aroma.
Servings and Timing
This recipe serves 10–12 people.
Prep Time: 30 minutes
Cook Time: 30 minutes
Chill Time (recommended): 2 hours
Total Time: About 3 hours
Variations
I like to fold crushed graham crackers into the filling for a little crunch and classic key lime pie texture.
For a coconut twist, I swap part of the buttermilk with coconut milk and top with toasted coconut flakes.
I sometimes use whipped cream cheese frosting instead of whipped cream for a tangier, sturdier finish.
Mini layer cakes or cupcakes with the same filling and topping also work beautifully for parties.
Storage/Reheating
I store leftover cake in an airtight container in the refrigerator for up to 4 days. The flavor deepens after chilling, and I actually prefer it after it’s been refrigerated for a while.
To serve, I let slices sit at room temperature for about 15–20 minutes for the best texture.
I don’t recommend freezing this cake because of the whipped cream frosting and custard-like filling, which can separate when thawed.
FAQs
What can I use if I can’t find key lime juice?
I use regular lime juice as a substitute, and it still gives the cake great flavor. If I want it extra tart, I add a splash of lemon juice for balance.
Can I make this cake ahead of time?
Yes, I bake the cake layers and make the filling a day in advance. I store them separately in the fridge and assemble just before serving.
Can I use bottled key lime juice?
I can, but I prefer fresh key limes or regular limes for a brighter, more natural flavor. Bottled juice works in a pinch though.
How do I keep the whipped cream frosting stable?
I whip the cream until stiff peaks form and make sure everything is cold before frosting. I also refrigerate the frosted cake until ready to serve to maintain structure.
Is this cake overly sweet?
Not at all. The lime juice and zest balance the sweetness perfectly, so I get a tart, refreshing bite every time.
Conclusion
This Key Lime Pie Cake is a vibrant, crowd-pleasing dessert that I always get compliments on. The zingy lime filling paired with tender cake and light whipped frosting makes it the perfect treat when I want something sweet but refreshing. Whether I serve it at a party or enjoy a slice on a sunny afternoon, it always hits the spot.
📖 Recipe:
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Key Lime Pie Cake
- Total Time: 3 hours
- Yield: 10–12 servings
- Diet: Vegetarian
Description
This Key Lime Pie Cake blends the zesty brightness of key lime pie with the fluffy sweetness of a classic layer cake. It features tangy citrus, silky lime filling, and whipped cream frosting, perfect for a refreshing summer dessert.
Ingredients
2 ½ cups all-purpose flour
2 ½ tsp baking powder
½ tsp salt
1 cup unsalted butter, softened
1 ¾ cups granulated sugar
4 large eggs
1 tbsp lime zest (from about 2 limes)
⅓ cup fresh key lime juice (or regular lime juice)
1 tsp vanilla extract
1 cup buttermilk
1 can (14 oz) sweetened condensed milk
4 large egg yolks
½ cup fresh key lime juice
1 tbsp lime zest
1 cup heavy cream
⅓ cup powdered sugar
1 tsp vanilla extract
Lime zest or thin lime slices for garnish
Instructions
- Preheat the oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
- In a bowl, whisk together flour, baking powder, and salt.
- In a separate bowl, cream butter and sugar until light and fluffy. Add eggs one at a time, then mix in lime zest, lime juice, and vanilla extract.
- Alternate adding the flour mixture and buttermilk, starting and ending with flour. Mix until just combined.
- Divide the batter evenly between the pans and bake for 25–30 minutes, or until a toothpick inserted comes out clean. Cool completely.
- To make the key lime filling, whisk sweetened condensed milk, egg yolks, lime juice, and zest in a medium bowl. Cook in a saucepan over low heat, stirring constantly for about 8 minutes until thickened. Let cool.
- Place one cake layer on a serving plate and spread with half of the lime filling. Add the second layer and spread the remaining filling, or reserve some for serving.
- For the frosting, beat heavy cream with powdered sugar and vanilla extract until stiff peaks form. Frost the top and sides of the cake.
- Garnish with lime zest or thin lime slices.
Notes
Crushed graham crackers can be folded into the filling for a pie-like texture.
Swap part of the buttermilk with coconut milk and top with toasted coconut flakes for a tropical twist.
Use whipped cream cheese frosting for a tangier, more stable alternative.
This recipe works well as cupcakes or mini cakes for parties.
Store in the fridge for up to 4 days; flavor improves after chilling.
Let slices sit at room temp for 15–20 minutes before serving.
Not recommended for freezing due to the whipped cream and filling.
- Prep Time: 30 minutes
- Cook Time: 30 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice
- Calories: 450
- Sugar: 35g
- Sodium: 220mg
- Fat: 24g
- Saturated Fat: 14g
- Unsaturated Fat: 8g
- Trans Fat: 0g
- Carbohydrates: 53g
- Fiber: 1g
- Protein: 6g
- Cholesterol: 120mg
