No-Bake Key Lime Icebox Cake

published Jun 25, 2024
summer
Key Lime Icebox Cake Recipe

This creamy, 6-layered dream is guaranteed to be the star of every summer party.

Serves9

Prep25 minutes

Cook5 minutes

Jump to Recipe
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angled shot of a single slice of key lime pie ice box cake on a small, flat, pink plate.
Credit: Photo: Alex Lepe; Food Styling: Spencer Richards

Key lime icebox cake is the no-bake dessert of your summer dreams. It features layers of graham crackers and an airy key lime cream that’s stuffed in between. An overnight stint in the fridge softens the crackers, making them more cakey, which helps marry them with the rich, indulgent flavor of key lime pie. And because there’s no need to turn on your oven, this light and tangy key lime icebox cake is perfect for those hot days. 

Why You’ll Love It

  • It’s as simple as it gets. The filling calls for a box of vanilla instant pudding mix, graham crackers, and bottled key lime juice (if you can’t get your hands on fresh). Plus, it doesn’t require you to heat up the oven.
  • If you love key lime pie, you’ll love this. Inspired by the tart pies that represent summers by the beach, it has layers of graham crackers and barely sweetened whipped cream mixed with a tart key lime custard. 
Credit: Photo: Alex Lepe; Food Styling: Spencer Richards

Key Ingredients in Key Lime Icebox Cake

  • Key lime curd: Our homemade curd gets its sweet-tart flavor from key lime juice. Rather than juice dozens of key limes, which can be hard to find, buy a bottle of readily available Nellie & Joe’s Key West Lime Juice.
  • Instant vanilla pudding: This quick mix only requires you add milk. Think of it as a lighter substitute for sweetened condensed milk in the typical key lime pie.
  • Whipped cream: Lightly sweetened whipped cream is folded into the key lime pudding mixture to give it a light-as-air texture.
  • Graham crackers: Graham crackers are layered in between the cream. After a night in the refrigerator, the crackers will soften and meld with the cream into a dessert that resembles a fancy layered torte, with thin layers of cake.

How to Make Key Lime Icebox Cake

  1. Make key lime curd. Use the microwave to whip up a quick curd in under 5 minutes. 
  2. Add the curd to vanilla pudding. Whisk instant pudding mix with milk then fold in the key lime curd.
  3. Whip cream. Use an electric hand mixer to whip heavy cream, powdered sugar, and vanilla extract into stiff peaks. Fold 2/3 of this into the custardy pudding mixture.
  4. Assemble the cake. Line a 8×8 baking dish with whole graham crackers, top with a third of the pudding mixture, then repeat two more times. Top off with the remaining whipped cream.
  5. Refrigerate overnight. Cover the cake and let it soften in the fridge for at least 8 hours.

Helpful Swaps

  • Lime juice: If you can’t get your hands on key lime juice or fresh key limes for the curd, substitute regular lime juice, which will lend a slightly more zippy, acidic flavor to the cake.
  • Lime curd: Substitute the homemade key lime curd with a generous 3/4 cup store-bought curd.
  • Whipped topping: Thaw one 8-ounce tub of frozen whipped topping and use it instead of the homemade whipped cream.

This is part of The Summer of Lazy Baking, featuring our easiest-ever recipes and grocery store hacks for making this the most delicious summer ever.

Key Lime Icebox Cake Recipe

This creamy, 6-layered dream is guaranteed to be the star of every summer party.

Prep time 25 minutes

Cook time 5 minutes

Serves 9

Nutritional Info

Ingredients

For the key lime custard:

  • 3 tablespoons

    unsalted butter

  • 1/3 cup

    granulated sugar

  • 1

    large egg

  • 1/8 teaspoon

    kosher salt

  • 1/3 cup

    bottled or freshly squeezed key lime juice

  • 1/2

    medium lime

  • 1

    (3.4-ounce) box instant vanilla pudding mix

  • 1 3/4 cups

    cold milk, any fat percentage

For the whipped cream:

  • 2 cups

    cold heavy cream

  • 3 tablespoons

    powdered sugar

  • 3/4 teaspoon

    vanilla extract

  • 1/8 teaspoon

    kosher salt

For assembly:

  • 1 1/2

    sleeves graham crackers (about 15 whole sheets), divided

  • 1/2

    medium lime

Instructions

Make the key lime custard:

  1. Cut 3 tablespoons unsalted butter into 3 pieces and place in a small microwave-safe bowl. Microwave in 20-second bursts until mostly melted, 40 to 50 seconds total (it will melt completely as it sits).

  2. Place 1/3 cup granulated sugar, 1 large egg, and 1/8 teaspoon kosher salt in a medium microwave-safe bowl and whisk until smooth. Add 1/3 cup key lime juice and the melted butter, and stir to combine. Microwave on high power in 1-minute intervals, whisking after each, until it thickens and coats the back of a spoon, 3 to 4 minutes total.

  3. Finely grate the zest of 1/2 medium lime into the curd and whisk to combine. Press a sheet of plastic wrap directly onto the surface of the curd and refrigerate until thickened, at least 45 minutes (it doesn’t need to be fully cold). If you’re strapped for time, cool the curd faster by placing it in an ice bath.

  4. Place 1 (3.4-ounce) box instant vanilla pudding mix and 1 3/4 cups cold milk in a large bowl and whisk until smooth. Add the key lime curd and whisk until smooth.

Make the whipped cream:

  1. Place 2 cups cold heavy cream, 3 tablespoons powdered sugar, 3/4 teaspoon vanilla extract, and 1/8 teaspoon kosher salt in the bowl of a stand mixer fitted with the whisk attachment. (Alternatively, use a large bowl and electric hand mixer or whisk by hand.) Beat on low speed, increasing to high speed, until stiff peaks form, 2 to 3 minutes.

  2. Transfer 1 cup of the whipped cream into the key lime custard and fold together with a flexible spatula until just combined. Add 1 more cup of the whipped cream and fold together until just combined and no streaks remain.

Assemble the cake:

  1. Arrange graham crackers in the bottom of an 8x8-inch, 2-inch deep baking dish, breaking them as needed to fit into a single tight, even layer. Evenly spread 1/3 of the pudding mixture (about 1 1/4 cups) over the crackers. Repeat layering the graham crackers and pudding mixture 2 more times. Dollop the remaining whipped cream on top and spread into an even layer.

  2. Cover and refrigerate for at least 8 hours or up to 2 days before serving. Finely grate the zest of 1/2 medium lime over the delight just before slicing into 9 pieces and serving.

Recipe Notes

Substitutions:

  • Lime juice: Substitute regular lime juice if you can’t find key lime juice.
  • Lime curd: Substitute generous 3/4 cup store-bought lime curd for the homemade key lime curd.
  • Whipped topping: Substitute 1 (8-ounce) tub frozen whipped topping for the homemade whipped cream. Thaw before using.

Stovetop method: If you don’t have a microwave, cook the lime curd on the stovetop by melting the butter in a small saucepan over low heat. Add the key lime juice, sugar, egg, and salt, and continue cooking, whisking constantly, until thickened (don’t let it come to a boil).

Make ahead: The curd can be made ahead and refrigerated for up to 1 week.

Storage: Leftover cake can be covered and refrigerated for up to 4 days. Cake slices can also be wrapped in aluminum foil and frozen for up to 3 months; thaw overnight in the freezer.