Pour the Key lime filling into the cooled crust.

Smooth the surface gently.

If you see obvious large air bubbles, lightly tap the pie dish against the counter.
Bake

Bake at 350°F (175°C) for approximately 15–17 minutes.

The pie is ready when the outer edges are set but the center still has a gentle jiggle when the pan is carefully nudged.

The center shouldn't look liquid, but it also shouldn't become completely rigid.

Don't wait for the filling to brown.
Cool & Chill

Remove the pie from the oven and place it on a wire rack.

Allow it to cool completely to room temperature.

Once cool, cover and refrigerate for at least 4 hours.

For the cleanest slices and best texture, chilling for 6 hours or overnight is even better.
Make the Stabilized Vanilla Whipped Cream

Wait until the pie is thoroughly chilled before preparing the topping.

Place the cold heavy whipping cream, powdered sugar, vanilla, and instant vanilla pudding mix in a chilled mixing bowl.

Using a hand mixer or stand mixer fitted with the whisk attachment, begin whipping on medium speed.

Increase to medium-high and continue beating until stiff peaks form.

Stop as soon as the cream holds its shape firmly.

Don't continue whipping unnecessarily or the cream can become grainy.
Decorate the Pie

Transfer the whipped cream to a piping bag fitted with a large star tip.

Pipe generous swirls around the edge of the chilled pie.

Alternatively, spoon the whipped cream over the center and create soft peaks with the back of a spoon.

Finish with fresh lime zest and thin lime slices.

Keep refrigerated until ready to serve.

Chef's Tips for the Best Key Lime Pie

• Use sweetened condensed milk, not evaporated milk. They're completely different products.
• Fresh lime juice gives the brightest flavor.
• Zest the limes before juicing them.
• Avoid grating the bitter white pith underneath the green peel.
• Prebake the crust so it stays firm beneath the creamy filling.
• Let the crust cool before adding the filling.
• Use full-fat sour cream for the best texture.
• Whisk the filling gently rather than whipping lots of air into it.
• Don't overbake the pie. A slight center jiggle is exactly what you want.
• Give the pie at least four hours to chill.
• Overnight chilling gives even cleaner slices.
• Make sure the cream is very cold before whipping.
• Instant vanilla pudding mix helps the whipped cream hold its piped shape longer.
• Add fresh lime garnishes relatively close to serving for the prettiest appearance.

The Secret to a Silky Key Lime Filling

The filling doesn't need flour or cornstarch because lime juice, sweetened condensed milk, and egg yolks naturally work together to create structure.

The acidity in the lime juice begins thickening the dairy before the pie even enters the oven.

Then gentle baking sets the egg yolks.

That's why overbaking isn't necessary. The center should still move slightly when the pie leaves the oven; it will continue firming as it cools and becomes substantially more set after refrigeration.

That combination creates a filling that's firm enough to slice but still exceptionally smooth and creamy.

Key Limes vs. Regular Limes

Traditional Key lime pie uses Key limes, which are smaller and have a distinctive floral, tart flavor.

If you can find fresh Key limes, they're excellent here.

However, regular Persian limes from a typical U.S. grocery store can also produce a delicious pie.

You'll need quite a few Key limes to produce a full cup of juice, so allow extra time if you're squeezing them by hand.

Whichever variety you use, freshly squeezed juice provides the brightest flavor.

The Secret to the Crust

Using a 50/50 combination of graham crackers and Nilla Wafers creates more complexity than either cookie alone.

Graham crackers provide toasted, slightly honeyed flavor, while vanilla wafers bring sweetness and vanilla richness.

Brown sugar reinforces those caramel notes.

The 10-minute prebake also matters: it melts the sugar and butter into the crumbs and helps create a cohesive crust that won't simply crumble away when you cut the pie.

Why Add Sour Cream?

Sour cream does two useful things.

First, it balances some of the sweetness from the condensed milk with a subtle tang.

Second, its fat contributes to the filling's rich, creamy mouthfeel.

Combined with a little heavy cream, it gives this pie an especially luxurious texture without hiding the sharp citrus flavor.

Stabilized Whipped Cream

Regular whipped cream is wonderful if you're serving the pie immediately.

For a decorated pie that may spend several hours in the refrigerator, the small amount of instant vanilla pudding mix provides additional stability.

It helps piped swirls retain their definition instead of gradually becoming soft and weepy.

The pudding mix should be used dry and directly from the package—don't prepare it as pudding first.

Delicious Variations

Coconut Key Lime Pie

Add ½ cup toasted shredded coconut to the crust and scatter additional toasted coconut over the whipped cream.

Key Lime Cheesecake Pie

Replace the sour cream with softened cream cheese for a denser cheesecake-inspired filling.

White Chocolate Key Lime

Drizzle the chilled pie lightly with melted white chocolate before adding whipped cream.

Key Lime Pie Bars

Press the crust into a parchment-lined rectangular pan, add the filling, bake until just set, chill thoroughly, and cut into squares.

Extra-Tart Key Lime Pie

Add additional finely grated lime zest rather than dramatically increasing the juice, which could alter the filling's consistency.