Key Lime Pie Cake
Key lime pie is something you either love or hate, I think. I like it but it is not ever going to be my first choice for a dessert. I know some people that could eat key lime pie every single day though. So when I created this key lime pie cake recipe, I made them try it for an honest review. The first version was pretty good, but I tweaked it some. This second version is loads better. One of my best friends has already placed her order for this key lime pie cake for her birthday in January.
Recipe Inspiration
Several years ago, my Mama sent me a key lime cake recipe to try and I made it for Homecoming at my church. I will never forget Mack Osteen raving about it. He even asked to take some of the cake home he loved it so much. When you grow up in a church full of incredible cooks; his wife included, it was a huge compliment that he loved the dessert I made so much. I tried to find the recipe to make it a few months ago and I couldn’t find it anywhere at my house or my Mama’s. So, I decided to recreate it and try to make it even better that I remembered.
My sister made a lemon bar cake from Baking with Blondie a couple of times. And every time she makes it, I say “that is the best cake ever!”. Part of what makes that lemon cake so incredibly good, is that the cake layers have a shortbread cookie crust and they are filled with lemon curd. So, I thought, I can do something like that with key lime!
About This Key Lime Cake
For the cake portion, I will be honest. I hardly ever make a cake from scratch. Over the years, I have found that it is hard to beat a doctored up cake mix. So, I started with a cake mix and added a short bread crust. I know that traditionally key lime pie has graham cracker crust. However, I just love the short bread so that is what I used, if you prefer graham crackers, feel free to mix it up. Instead of using the icing between the layers, I made a filling of key lime juice, whipping cream and sweetened condensed milk. This filling is tart and gives the kick the key lime pie cake needs. I finished with a lime buttercream on the outside of the cake. It is the perfect sweet and tart taste and is sure to please any key lime pie lover you have in your house!
I am no professional baker and I am most definitely not a great decorator. I just smoothed the icing on the cake, piped some areas on the top and used fresh limes and short bread cookie halves to make it look pretty. If you or your friends and family are key lime pie fans, please give this recipe a try. I would love to know if you like it, so please leave me a comment below!
Key Lime Pie Cake
Ingredients
Shortbread Crust
- 2 packages Sandies Shortbread cookies (11 oz packages)
- 1 1/2 sticks butter, melted
Key Lime Cake
- 1 box Duncan Hines Yellow Cake Mix
- 1 cup All Purpose Flour
- 1 cup granulated sugar
- 1 cup sour cream
- 1/4 tsp salt
- 1 stick melted butter
- 1 cup milk
- 4 eggs
- t tsp vanilla extract
- 2 tbsp key lime juice
- Zest of 1 lime
Key Lime Filling
- 1 14oz can sweetened condensed milk
- 1/2 cup key lime juice
- 2 tsp lime zest
- 1 1/2 cups heavy whipping cream
Key Lime Buttercream Icing
- 2 sticks butter
- 1 8oz block of cream cheese
- 1/4 cup heavy whipping cream or milk
- 5 cups powdered sugar
- 1 tbsp key lime juice
- 1 tsp lime zest
- 1 tsp vanilla extract
Instructions
Shortbread Crust
- Pulse the cookies in a food processor until crumbly, add 1 stick of melted butter and mix in food processor until a crust forms. Press crust into 3, 8" cake pans that have been greased and floured. You can use a glass or measuring cup to flatten it easier. Set aside and make the cake batter. If you prefer graham crackers, just use them to make a crust instead.
Key Lime Cake
- Place all ingredients in a stand mixer and begin on low to combine. Increase the speed and scrap the sides and bottom of bowl. Let mix for 2-3 minutes, scraping down the sides and bowl again. Divide and pour the batter over the crust mixture in the 3 cake pans. Bake at 350° for 35-40 minutes, using a toothpick that comes out clean to ensure it is done. Let cool completely, I flip mine out of the pan to cool on wax paper so they don't stick.
Key Lime Filling
- In a small bowl, combine sweetened condensed milk, key lime juice and lime zest and set aside. In a large mixing bowl, whip the heavy whipping cream until stiff peaks form and then fold in the lime juice mixture until it is well combined. Once the cake is cooled, place the first layer on the cake plate with the crust side down, poke holes in the cake to allow mixture to seep into the layers, top with 1/2 of the key lime filling and add the second layer, repeat with the other 1/2 of the key lime filling and add the third layer. The crust should be on the bottom and the cake portion of the layer on the top for easier icing. Set in the fridge to chill and set up for an hour. Make icing while it is chilling.
Key Lime Buttercream Icing
- Cream softened butter and softened cream cheese for 2-3 minutes until well combined. Add key lime juice and zest and continue beating. Slowly add powdered sugar and blend, add heavy whipping cream or milk until you obtain the right consistency. I just add a little bit at a time. You might need more, but add a lot at once. Once it is correct, apply a crumb coat to the chilled cake, chill again for 30 minutes and then ice the cake completely. You can decorate with fresh limes and shortbread cookies.
Notes

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