Copycat Costco Key Lime Pie
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Costco Key Lime Pie is loaded with bright citrus flavor and tucked inside a crisp graham cracker crust, then finished with clouds of real whipped cream. Sweetened condensed milk brings that classic silky texture, while sour cream adds depth and tang. It’s smooth. It’s tart. It’s sweet. It’s sunshine in a slice. And it’s so easy to make this show-stopping dessert from scratch, there’s no reason to keep buying key lime pie at Costco at all!!
Table of Contents
Costco Key Lime Pie
As a Florida girl, let me tell you… Key Lime Pie isn’t just dessert. It’s a rite of passage.
I grew up on the real-deal stuff. Tart, creamy, and piled high with whipped cream. And let’s just say… I’ve had my fair share of bad imitations.
So when I set out to copycat the Costco version, I wasn’t messing around. This one has that classic Florida flavor… zingy citrus, buttery graham crust, and a filling so smooth it practically hums.
I’ve brought copycat Costco key lime pie to BBQs, birthdays, and yes, even breakfast… and it always disappears. One bite and you’ll see why it’s a sunshine state legend.
Can’t get enough of that Florida-famous flavor? Try key lime cheesecake or these thick, pie-inspired cookies next!
INGREDIENT NOTES
- Sweetened Condensed Milk: Use full-fat for the best texture and richness. In a pinch, coconut condensed milk will work, but note the smaller can size and slight flavor change.
- Key Lime Juice: Key limes are smaller (and sweeter) than the typical limes you find at the store, so you’ll need at least a dozen for this recipe.
Freshly squeezed juice gives the most authentic flavor, but Nellie and Joe’s bottled key lime juice is a close second. - Sour Cream: Adds smooth tang and helps the pie filling set up creamy and thick. Greek yogurt works in a pinch.
- Egg Yolks: These make the filling extra dreamy and luxuriously smooth. Use room temperature yolks to help things emulsify evenly.
- Graham Cracker Crust: Homemade tastes the best and holds together a bit better than store-bought crusts, but take the shortcut if you need it!
- Whipped Cream: Skip the canned stuff and make it from scratch! Add some powdered sugar and vanilla extract when whipping heavy cream for a sweet and stable topping.
VARIATIONS
Tropical Twist: Add a splash of coconut extract or shredded toasted coconut to the filling.
Mango Key Lime Pie: Fold ¼ cup mango purée into the filling before baking.
Extra Tangy: Add 1 tablespoon of lime zest to the filling for a citrus-loaded bite.
Mini Pies: Divide the filling into mini tart pans or cupcake liners with graham cracker crust.
Lower Sugar: Use low-sugar sweetened condensed milk and skip the sugar in the crust.
KEY LIME PIE COSTCO FAQ
Yes, but the flavor will be a little less floral and a little sharper. Still yummy though!
The key lime filling will be just set, especially around the edges, but still jiggly in the center. Don’t worry, it’ll finish setting once it’s been cooled and chilled.
Yes, as does the homemade version. Wrap tightly in plastic and enjoy within 3 days. It’s best to add the whipped cream just before serving so it doesn’t deflate or weep.
Want to freeze it instead? After wrapping in plastic, add a layer of foil. Freeze for up to 2 months and thaw in the fridge before serving. Again, wait to add the whipped cream until it’s time to serve.
After testing this recipe side-by-side with the key lime pie at Costco, I focused on building the same silky texture and bold citrus flavor but with fresher ingredients and more balance.
The key to a luscious, creamy filling is emulsifying the egg yolks with the sweetened condensed milk and sour cream. When gently baked, the proteins slowly set without curdling, giving you that custard-like texture that holds its shape but melts in your mouth.
Letting it chill fully is non-negotiable. That cold set transforms the filling from soft to sliceable, and the whipped cream? Total harmony.
This Costco key lime pie recipe is foolproof, fresh, and always a crowd-pleaser.
DONNA’S PRO TIPS
- Use room temp ingredients. It helps the filling blend smoothly without lumps.
- Don’t overbake. The pie should jiggle slightly in the center. It’ll finish setting in the fridge.
- Let it chill completely. Three hours minimum. More is even better!
- Whip the cream cold. A cold bowl and beaters make the fluffiest whipped cream.
- Add some flair. Pipe the whipped cream with a star tip, then sprinkle with lime zest. You can even add lime slices or sugared peels.
- Make it ahead. This pie is even better the next day. It’s a party trick that keeps on giving!
TOOLS NEEDED
- 9-inch pie plate
- Mixing bowls
- Whisk or silicone spatula
- Hand or stand mixer
- Measuring cups and spoons
- Citrus juicer and zester
- Offset spatula or spoon for spreading
- Cooling rack
Enjoy!
With love, from our simple kitchen to yours.
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Copycat Costco Key Lime Pie
Ingredients
For the Crust:
- 1 1/2 cups graham cracker crumbs
- 5 tablespoons granulated sugar
- 6 tablespoons unsalted butter, melted
For the Filling:
- 2 14-ounce cans sweetened condensed milk
- 3/4 cup fresh key lime juice, about 15 key limes or bottled key lime juice
- 1/2 cup sour cream, room temperature
- 2 large egg yolks, room temperature
For the Whipped Topping:
- 1 cup heavy whipping cream, chilled
- 1 tablespoon powdered sugar
- 1 teaspoon pure vanilla extract
Instructions
- Preheat the Oven: Preheat oven to 350°F. Set aside a 9-inch pie plate.
- Make the Crust: In a medium mixing bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Stir until the texture resembles wet sand.
- Press the Crust: Press the mixture into the pie dish, covering the bottom and sides evenly. Use the back of a spoon or measuring cup to press it firmly.
- Bake the Crust: Bake for 8 minutes. Remove from the oven and set aside to cool completely.
- Make the Filling: In a large mixing bowl, whisk together sweetened condensed milk, key lime juice, sour cream, and egg yolks until smooth and fully combined.
- Add the Filling to the Crust: Pour the filling into the cooled crust. Use a spatula to smooth the top.
- Bake the Pie: Bake for 15 to 20 minutes, just until the filling is set but still slightly jiggly in the center. Do not allow the top to brown.
- Cool the Pie: Place the pie on a cooling rack and let it cool at room temperature for 30 minutes.
- Chill the Pie: Cover with plastic wrap and refrigerate for at least 3 hours, or until fully set and chilled.
- Make the Whipped Topping: Using a stand or hand mixer, beat the cold heavy cream on high speed until soft peaks form. Add powdered sugar and vanilla extract. Continue whipping until stiff peaks form.
- Top the Pie: Spread or pipe the whipped cream over the chilled pie. Garnish with lime zest or crushed graham crackers, if desired.
- Serve: Serve cold. Store leftovers in the refrigerator.
Donna’s Notes
Nutrition
All nutritional information is based on third party calculations and is only an estimate. Each recipe’s nutritional value will vary depending on the ingredients used, measuring methods, and portion sizes.
Originally published August 2025
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We’re Donna and Chad, the dream team behind The Slow Roasted Italian. Our focus is on taking complicated OUT of the kitchen. Life is busy enough, making meals should be fast and easy, to help make your life as simple as possible. Read More >>
