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Key Lime Pie Mousse

It’s the oat crumble that keeps us coming back.


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key lime pie mousse

Photo: Rachel Vanni; Food Styling: Makinze Gore

Nothing says summer quite like a tart key lime pie. That being said, when you’re not in the mood to make a whole pie (or are looking for the cutest shareable dessert), then this mini dessert is the one for you. This mousse is every bit as refreshing, with a fluffy texture and a crispy oat crumble we could eat on its own. The sweet and tart combo hits all of the right notes for a quintessential summer dessert—it’s the perfect refreshing bite after too-hot days in the sun.

Concerning the limes: Key limes are more tart than traditional limes; they’re worth finding for this mousse. We promise, your effort will be more than rewarded. 😉


For the Crumble

  • 4 graham crackers
  • 3/4 c. rolled oats
  • 1/3 c. packed light brown sugar
  • 3 tbsp. all-purpose flour
  • 6 tbsp. cold butter, cubed

For the Mousse

  • 1 1/2 c. heavy cream
  • 1/4 c. powdered sugar
  • 1 c. sweetened condensed milk
  • 1/3 c. freshly squeezed key lime juice
  • 1 tsp. pure vanilla extract
  • Green food coloring (optional) 

  • Key lime wedges, for garnish


Step 1

Preheat oven to 350°. In a food processor, pulse graham crackers into fine crumbs. In a medium bowl, combine crushed graham crackers, oats, brown sugar, and flour. Add butter and use your hands to cut into mixture until pea-sized and mixture starts to hold together. Spread mixture into an even layer on a baking sheet. Bake until golden and crisp, about 20 minutes, stirring halfway through. Let cool.

Step 2

Make mousse: In a large bowl, using a hand mixer (or in the bowl of a stand mixer fitted with the whisk attachment), beat cream and powdered sugar into stiff peaks. Remove about 1 cup of whipped cream to reserve for topping.

Step 3

In a medium bowl, combine condensed milk, lime juice, vanilla, and a small drop of food coloring, if using. Add to bowl of whipped cream. Gently fold in until just combined.

Step 4

Assemble: Add about ¼ cup of crumble to the bottom of 4 glasses. Top with two large spoonfuls of mousse, then repeat with another layer of crumble and mousse.

Step 5

Place reserved whipped cream in a piping bag fitted with a large closed star tip, and pipe onto mousse. Top with any remaining crumble and a lime wedge in each glass.

Step 6

Keep refrigerated until ready to serve.


Photo: Rachel Vanni; Food Styling: Makinze Gore

Makinze is currently senior food editor at Delish, where she develops recipes, creates, and hosts recipe videos and is our current baking queen. She is our expert pie crimper, believes you should always have the ingredients for chocolate chip cookies on hand, and everyone needs to know a perfect roast chicken recipe.

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This post originally appeared on Delish and was published August 10, 2023. This article is republished here with permission.

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