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Key Lime Cups

By America's Test Kitchen Kids

Published on January 4, 2023

Time

35 minutes, plus 1¾ hours cooling and chilling time

Yield

Serves 4

What Kids Are Saying

“I liked squishing the graham crackers! It was hard to wait to try it while it was in the fridge.” —Isabelle, recipe tester, age 6

Key Lime Cups

Ingredients

graham crackers, broken into pieces1 tablespoon unsalted butter ¼ cup (2 ounces/57 grams) cream cheese 1 (14-ounce) can sweetened condensed milk, opened1 teaspoon grated lime zest plus ⅓ cup juice, zested and squeezed from 3 limes2 tablespoons water 1 large egg yolk Pinch table salt Whipped cream (optional; see note, below)

Before You Begin

To make 2 cups whipped cream: In large bowl, combine 1 cup cold heavy cream, 1 tablespoon sugar, and 1 teaspoon vanilla extract. Use electric mixer on medium-low speed to whip cream for 1 minute. Increase speed to high and whip until cream is smooth and thick, about 1 minute. Stop mixer and lift beaters out of cream. If cream clings to beaters and makes soft peaks that stand up on their own, you’re done. If not, keep beating and check again in 30 seconds. Don’t overwhip cream. 

Instructions

  1. Adjust oven rack to middle position and heat oven to 300 degrees.
  2. Place graham cracker pieces in large zipper-lock plastic bag. Press out as much air as possible from bag and seal bag. Use rolling pin to gently crush graham crackers into crumbs (see “Step-by-Step: How to Make Graham Cracker Crumbs,” below). Set aside.
  3. In small microwave-safe bowl, combine graham cracker crumbs and butter. Heat in microwave until crumbs are toasted, about 1 minute. Stir with rubber spatula to combine.
  4. Place cream cheese in large microwave-safe bowl. Heat cream cheese in microwave until softened, 10 to 15 seconds. Whisk softened cream cheese until very smooth.
  5. Add condensed milk, lime zest and juice, water, egg yolk, and salt to bowl with cream cheese. Whisk until well combined and smooth.
  6. Divide mixture evenly among 4 (4-ounce) ramekins. Place ramekins on rimmed baking sheet.
  7. Place baking sheet in oven. Bake until filling is set and no longer jiggles when baking sheet is gently shaken, about 6 minutes (ask an adult for help).
  8. Use oven mitts to remove baking sheet from oven and place on cooling rack (ask an adult for help). Let key lime cups cool on cooling rack for 45 minutes.
  9. Cover ramekins with plastic wrap. Place in refrigerator until filling is chilled and firm, at least 1 hour or up to 2 days. To serve, dollop with whipped cream (if using), and sprinkle with graham cracker topping.
Key Lime Cups
Photography by Kevin White. Styling by Ashley Moore.

Time

35 minutes, plus 1¾ hours cooling and chilling time

Yield

Serves 4

What Kids Are Saying

“I liked squishing the graham crackers! It was hard to wait to try it while it was in the fridge.” —Isabelle, recipe tester, age 6

Ingredients

graham crackers, broken into pieces
1 tablespoon unsalted butter
¼ cup (2 ounces/57 grams) cream cheese
1 (14-ounce) can sweetened condensed milk, opened
1 teaspoon grated lime zest plus ⅓ cup juice, zested and squeezed from 3 limes
2 tablespoons water
1 large egg yolk
Pinch table salt
Whipped cream (optional; see note, below)

Test Kitchen Techniques

Ingredients

graham crackers, broken into pieces
1 tablespoon unsalted butter
¼ cup (2 ounces/57 grams) cream cheese
1 (14-ounce) can sweetened condensed milk, opened
1 teaspoon grated lime zest plus ⅓ cup juice, zested and squeezed from 3 limes
2 tablespoons water
1 large egg yolk
Pinch table salt
Whipped cream (optional; see note, below)

Test Kitchen Techniques

Ingredients

graham crackers, broken into pieces
1 tablespoon unsalted butter
¼ cup (2 ounces/57 grams) cream cheese
1 (14-ounce) can sweetened condensed milk, opened
1 teaspoon grated lime zest plus ⅓ cup juice, zested and squeezed from 3 limes
2 tablespoons water
1 large egg yolk
Pinch table salt
Whipped cream (optional; see note, below)

Test Kitchen Techniques

Why This Recipe Works

We took the elements of classic key lime pie—a toasty graham cracker crust and a creamy, tart custard—and made them so simple, even the youngest chefs can tackle these pint-sized desserts. Instead of a blind-baked crust, we toast graham crackers crumbs and butter in the microwave for a crunchy topping. And there’s no fussy custard to cook on the stovetop (and no eggs to temper!), just whisk together the ingredients and bake. This recipe contains lime zest and lime juice. Have kids smell and taste a bit of lime juice and then a bit of lime zest. What do they notice? Lime juice contains all of the fruit’s tart taste, while the zest is full of what we think of as “lime” flavor.

Before You Begin

To make 2 cups whipped cream: In large bowl, combine 1 cup cold heavy cream, 1 tablespoon sugar, and 1 teaspoon vanilla extract. Use electric mixer on medium-low speed to whip cream for 1 minute. Increase speed to high and whip until cream is smooth and thick, about 1 minute. Stop mixer and lift beaters out of cream. If cream clings to beaters and makes soft peaks that stand up on their own, you’re done. If not, keep beating and check again in 30 seconds. Don’t overwhip cream. 

Instructions

  1. Adjust oven rack to middle position and heat oven to 300 degrees.
  2. Place graham cracker pieces in large zipper-lock plastic bag. Press out as much air as possible from bag and seal bag. Use rolling pin to gently crush graham crackers into crumbs (see “Step-by-Step: How to Make Graham Cracker Crumbs,” below). Set aside.
  3. In small microwave-safe bowl, combine graham cracker crumbs and butter. Heat in microwave until crumbs are toasted, about 1 minute. Stir with rubber spatula to combine.
  4. Place cream cheese in large microwave-safe bowl. Heat cream cheese in microwave until softened, 10 to 15 seconds. Whisk softened cream cheese until very smooth.
  5. Add condensed milk, lime zest and juice, water, egg yolk, and salt to bowl with cream cheese. Whisk until well combined and smooth.
  6. Divide mixture evenly among 4 (4-ounce) ramekins. Place ramekins on rimmed baking sheet.
  7. Place baking sheet in oven. Bake until filling is set and no longer jiggles when baking sheet is gently shaken, about 6 minutes (ask an adult for help).
  8. Use oven mitts to remove baking sheet from oven and place on cooling rack (ask an adult for help). Let key lime cups cool on cooling rack for 45 minutes.
  9. Cover ramekins with plastic wrap. Place in refrigerator until filling is chilled and firm, at least 1 hour or up to 2 days. To serve, dollop with whipped cream (if using), and sprinkle with graham cracker topping.

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