Quick Recipe Version (TL;DR)
Quick Ingredients
- Graham cracker crumbs, 1 1/2 cups (about 12 full sheets)
- Granulated sugar, 3 tablespoons
- Kosher salt, 1/4 teaspoon
- Unsalted butter (melted), 6 tablespoons (85 g)
- Sweetened condensed milk, 1 can (14 ounces / 397 g)
- Key lime juice (bottled or fresh), 3/4 cup (180 ml)
- Key lime zest, 2 teaspoons (plus more for garnish)
- Egg yolks, 4 large
- Heavy cream (cold), 1 cup (240 ml)
- Powdered sugar, 2 tablespoons
- Vanilla extract, 1/2 teaspoon
Do This
- 1) Heat oven to 350°F (177°C). Mix crumbs, sugar, salt, and melted butter; press into a 9-inch pie plate.
- 2) Bake crust 10 minutes; cool 10 minutes.
- 3) Whisk condensed milk + zest; whisk in yolks; whisk in key lime juice until thickened.
- 4) Pour filling into crust; bake 15 minutes (center should jiggle slightly).
- 5) Cool on rack 1 hour, then chill uncovered until fully cold, at least 4 hours.
- 6) Whip cream + powdered sugar + vanilla to medium peaks; spread or pipe on chilled pie.
- 7) Finish with extra lime zest; slice with a hot, clean knife.
Why You’ll Love This Recipe
- Bright, tangy lime flavor balanced by creamy sweetened condensed milk.
- A crunchy, buttery graham cracker crust that stays crisp under the filling.
- Simple ingredients and a quick bake for a clean, sliceable set.
- Airy whipped cream on top makes each bite feel light and fresh.
Grocery List
- Produce: Key limes (or regular limes for zest), optional extra lime for garnish
- Dairy: Unsalted butter, heavy cream
- Pantry: Graham crackers (or graham cracker crumbs), granulated sugar, kosher salt, sweetened condensed milk, powdered sugar, vanilla extract
- Refrigerated: Large eggs
Full Ingredients
Graham Cracker Crust
- Graham cracker crumbs, 1 1/2 cups (about 12 full sheets crushed)
- Granulated sugar, 3 tablespoons
- Kosher salt, 1/4 teaspoon
- Unsalted butter, melted and slightly cooled, 6 tablespoons (85 g)
Key Lime Filling
- Sweetened condensed milk, 1 (14-ounce / 397 g) can
- Key lime zest, 2 teaspoons (from about 4–6 key limes; or use regular lime zest)
- Large egg yolks, 4
- Key lime juice, 3/4 cup (180 ml) (fresh or bottled)
Whipped Cream Topping
- Heavy cream, very cold, 1 cup (240 ml)
- Powdered sugar, 2 tablespoons
- Vanilla extract, 1/2 teaspoon
To Finish
- Extra key lime (or lime) zest, 1 to 2 teaspoons
- Optional: thin lime slices or twists for garnish
Step-by-Step Instructions
Step 1: Prep the pan and heat the oven
Arrange a rack in the center of the oven and preheat to 350°F (177°C). Set out a 9-inch pie plate (standard depth). If you like clean slices, you can lightly grease the plate, but it’s not required for a graham crust.
Step 2: Make and press in the graham cracker crust
In a medium bowl, mix 1 1/2 cups graham cracker crumbs, 3 tablespoons granulated sugar, and 1/4 teaspoon kosher salt. Pour in 6 tablespoons melted butter and stir until the mixture looks evenly moistened (like damp sand).
Tip the crumbs into the pie plate. Use the bottom of a measuring cup to press firmly into an even layer across the bottom and up the sides. Press especially well where the sides meet the bottom; that helps the crust hold together when sliced.
Step 3: Bake the crust until set and fragrant
Bake the crust for 10 minutes, until lightly deeper in color and smelling toasty. Transfer to a wire rack and let cool for 10 minutes. Keep the oven on at 350°F (177°C).
Step 4: Whisk the key lime filling until thick and smooth
In a medium bowl, whisk the sweetened condensed milk with the 2 teaspoons key lime zest. Whisk in the 4 egg yolks until fully blended.
Slowly whisk in the 3/4 cup (180 ml) key lime juice. As you whisk, you’ll notice the filling thicken slightly; that’s exactly what you want for a silky, sliceable pie.
Step 5: Fill the crust
Pour the filling into the warm crust (it’s fine if the crust is still a little warm). Gently tap the pie plate on the counter a couple of times to pop any larger air bubbles and help the top level out.
Step 6: Bake briefly, then cool
Bake at 350°F (177°C) for 15 minutes. The edges should look set, and the center should still have a slight jiggle (it will firm up as it cools and chills).
Cool the pie on a wire rack for 1 hour at room temperature.
Step 7: Chill until fully cold and sliceable
Transfer the pie to the refrigerator and chill uncovered until completely cold and firm, at least 4 hours (overnight is even better if you have time). Chilling is what gives you clean slices and that classic creamy texture.
Step 8: Make the whipped cream and finish the pie
Right before serving, make the topping. In a cold mixing bowl, combine 1 cup cold heavy cream, 2 tablespoons powdered sugar, and 1/2 teaspoon vanilla. Whip until medium peaks form (soft, billowy peaks that hold their shape but still look smooth).
Spread the whipped cream over the chilled pie or pipe it on in swirls. Finish with 1 to 2 teaspoons extra lime zest and, if you like, a few thin lime slices or twists.
For the neatest slices, dip a knife in hot water, wipe dry, and slice. Wipe between cuts.
Pro Tips
- Fresh vs. bottled key lime juice: Fresh key lime juice is fantastic but time-consuming; a good bottled key lime juice works beautifully here. Either way, use fresh zest for the brightest aroma.
- Don’t overbake: The filling should still jiggle slightly in the center when it comes out. Overbaking can make the texture less creamy.
- Press the crust firmly: A tight, well-compacted crust slices cleaner and holds together better.
- Chill long enough: Four hours is the minimum. If you want picture-perfect slices, chill overnight.
- Whipped cream timing: Add whipped cream close to serving for the fluffiest texture (especially if you’re not using stabilizers).
Variations
- Coconut key lime pie: Replace 1/2 cup of graham crumbs with 1/2 cup sweetened shredded coconut (pulse briefly), and toast a little coconut for the top.
- Ginger snap crust: Swap graham crackers for gingersnaps for a spicier crunch that pairs beautifully with lime.
- Mini key lime pies: Press crust into a muffin tin lined with paper liners; bake crusts 8 minutes, fill, then bake 10–12 minutes. Chill and top with whipped cream.
Storage & Make-Ahead
Refrigerator: Store the pie covered in the refrigerator for up to 4 days. For best texture, add whipped cream within 24 hours of serving (or store whipped cream separately and top slices as you go).
Make-ahead: You can bake and chill the pie (without whipped cream) up to 2 days ahead. Whip the cream and garnish right before serving.
Freezing: Freeze the pie (without whipped cream) tightly wrapped for up to 1 month. Thaw overnight in the refrigerator. Add fresh whipped cream and zest before serving.
Nutrition (per serving)
Approximate, per slice (1/8 of pie): Calories: 430; Carbohydrates: 46 g; Protein: 7 g; Fat: 25 g; Saturated Fat: 15 g; Cholesterol: 150 mg; Sodium: 220 mg; Fiber: 1 g; Sugars: 36 g.
