Costco Key Lime Dessert Cups

These Costco key lime dessert cups taste just like the bakery version but come together in your own kitchen tonight. Creamy, tangy, and genuinely easy to make.

Costco key lime dessert cups are mini graham cracker-crusted key lime pies baked in individual cups and topped with fresh whipped cream. This recipe makes 8 to 10 servings, delivers a creamy-tangy filling with a buttery crust in every bite, and works well for potlucks, holiday dinners, or any weeknight when you want pie without slicing a whole one. Here’s everything you need to make it perfectly.

I started making these costco key lime dessert cups after my daughter kept asking for the bakery version every time we went shopping. Turns out the filling sets up firmer if your egg yolks are actually at room temperature — I learned that the hard way with a batch that never fully set. Once I fixed that one detail, these came out right every single time after that.

Why You’ll Love These Costco Key Lime Dessert Cups

The filling is tart and creamy at once, landing somewhere between a cheesecake and a citrus pudding. You get a buttery graham crust on the bottom, a silky key lime layer in the middle, and softly whipped cream on top, and none of it requires slicing a whole pie.

They’re simple enough for a random Tuesday and pretty enough to bring to a holiday dinner. Kids ask for seconds, adults pretend they’re only having one, and cleanup takes about five minutes.

What Ingredients Do You Need for Key Lime Dessert Cups?

Ingredient Group	Ingredient	Amount	Notes
For the Crust	Graham cracker crumbs	1 ½ cups	fine crumbs work best
For the Crust	Granulated sugar	5 tablespoons
For the Crust	Unsalted butter	6 tablespoons	melted
For the Filling	Sweetened condensed milk	2 (14-ounce) cans
For the Filling	Fresh key lime juice	¾ cup	about 15 key limes
For the Filling	Sour cream	½ cup	room temperature
For the Filling	Large egg yolks	2	room temperature
For the Whipped Topping	Heavy whipping cream	1 cup	chilled
For the Whipped Topping	Powdered sugar	1 tablespoon
For the Whipped Topping	Pure vanilla extract	1 teaspoon

Real key lime juice makes a noticeable difference here, but bottled key lime juice works fine if you can’t find the actual limes or don’t want to juice fifteen of them. Room-temperature egg yolks and sour cream matter more than people think — cold dairy going into that condensed milk mixture is part of what causes a lumpy, uneven filling.

This is basically a copycat Costco key lime pie, just scaled down into single-serve cups so nobody has to fight over the crust-to-filling ratio.

How to Make Key Lime Dessert Cups Step by Step

Make the Crust

1. Preheat your oven to 350°F (175°C).
2. Place 8 to 10 oven-safe dessert cups or ramekins on a baking tray.
3. In a medium mixing bowl, stir together the graham cracker crumbs, granulated sugar, and melted butter until evenly moistened.
4. Divide the crust mixture evenly among the dessert cups, using about 2 to 3 tablespoons per cup.
5. Press the crumbs firmly into the bottom of each cup with the back of a spoon or a small measuring cup.

💡 A flat-bottomed measuring cup packs the crust down more evenly than a spoon does.

6. Bake the crusts for 5 to 6 minutes.
7. Remove the crusts from the oven.
8. Let the crusts cool while you prepare the filling.

Make the Filling

9. In a large mixing bowl, whisk together the sweetened condensed milk, key lime juice, sour cream, and egg yolks until smooth and creamy.

Pro Tip: Room-temperature egg yolks and sour cream blend into the condensed milk far more smoothly than cold ones, which prevents a grainy filling.

10. Evenly spoon or pour the key lime filling over the cooled crusts, filling each cup nearly to the top.

Bake and Chill

11. Bake for 10 to 12 minutes, or until the filling is just set with a slight jiggle in the center.
12. Do not allow the tops to brown.

💡 A slight jiggle in the middle means it’s done — the filling firms up completely once it’s chilled.

13. Let the dessert cups cool at room temperature for about 20 to 30 minutes.
14. Cover and refrigerate for at least 3 hours, or until thoroughly chilled.

Pro Tip: Skipping the full 3-hour chill is the number one reason the filling looks soft or soupy when you dig in.

Make the Whipped Topping

15. Beat the chilled heavy whipping cream until soft peaks form.
16. Add the powdered sugar and vanilla extract.
17. Continue beating until stiff peaks form.
18. Pipe or spoon the whipped cream onto each chilled dessert cup.
19. Garnish with fresh lime zest, a thin lime slice, or crushed graham crackers, if desired.
20. Serve the Costco key lime dessert cups cold, and store leftovers covered in the refrigerator for up to 3 days.

Expert Tips for Perfect Costco Key Lime Dessert Cups

Pro Tips for Success

The key to a smooth, silky filling is starting with room-temperature egg yolks and sour cream before whisking everything together. For best results, use a fine strainer on your key lime juice first, since stray seeds or pulp can throw off the texture. The most common mistake is pulling the cups out of the oven too early — instead, look for a filling that jiggles gently in the center but isn’t liquid at the edges.

Costco key lime dessert cups set up best when they get the full 3 hours in the fridge, so resist the urge to serve them early. Chilled heavy cream whips to stiff peaks faster than room-temperature cream, so keep your bowl and beaters cold if your kitchen runs warm.

Delicious Variations

Quick Version: Skip individual cups and press the crust into a single 9-inch pie dish, then bake and fill as directed, adding a few extra minutes to the bake time for the thicker layer.

Alternative Ingredients: Regular fresh lime juice works if key limes aren’t available, though the flavor turns slightly less floral and a bit more sharply tart.

Gluten-Free Version: Swap in gluten-free graham cracker crumbs for the crust, and double-check that your other packaged ingredients are labeled gluten-free.

Troubleshooting Common Problems

Problem: The filling never fully sets, even after chilling. Solution: This almost always traces back to cold egg yolks or sour cream, or pulling the cups from the oven before the edges look set — bake a couple minutes longer next time.

Problem: The crust crumbles apart instead of holding together. Solution: Press it down harder and more evenly with a flat-bottomed cup, and make sure the melted butter fully coated the crumbs before you divided the mixture.

Problem: The top of the filling browned instead of staying pale. Solution: Your oven likely runs hot, so check at the 8-minute mark next time and pull the cups the moment the centers stop looking liquid.

How to Store and Reheat Key Lime Dessert Cups

Storage Method	Duration	Best Practice
Room Temperature	2 hours max	keep covered, away from direct sun
Refrigerator	up to 3 days	cover tightly to keep the topping fresh
Freezer	not recommended	dairy-based filling separates when thawed

There’s no reheating step here since these are meant to be served cold straight from the fridge. If the whipped topping starts looking a little deflated after a day or two, just pipe on a fresh spoonful before serving again. Leftover crust crumbs or extra filling can go straight into a small jar for a mini parfait the next day instead of getting tossed.

FAQs About Costco Key Lime Dessert Cups

Honestly, if you make these, you have to let me know how they turn out. Save this to your dessert board on Pinterest so you don’t lose it, and drop a comment below with any tweaks you tried — I read every single one. If key lime isn’t your thing right now, this butter pecan sheet cake or these blueberry coffee cake muffins are worth a look too, and if you want something to sip alongside dessert, try this strawberry syrup for matcha.

Creamy, tangy Costco key lime dessert cups with a buttery graham crust and fluffy whipped cream on top — an easy copycat dessert ready for your next potluck. Save this recipe for later.