These Key Lime Mousse Cups are the perfect no-bake dessert—light, tangy, and irresistibly creamy. With a buttery graham cracker crunch layered under a rich, citrus-kissed mousse, they deliver all the flavor of a classic key lime pie without ever turning on the oven. Serve them in individual jars or ramekins for a refreshing make-ahead treat that’s as elegant as it is easy.

Ingredients

For the Graham Cracker Crumbs

• 2 Tablespoons unsalted butter
• 4 full-size sheets graham cracker, coarsely crushed
• 1 Tablespoon granulated sugar
• 1 pinch kosher salt

For the Mousse and Serving

• 8 ounces cream cheese, at room temperature
• 1 2/3 cups cold heavy cream, divided
• 1 (14-ounce) can sweetened condensed milk
• 1 teaspoon finely grated lime zest, plus more for garnish
• 1/2 cup freshly squeezed lime juice or Key lime juice
• 1/3 cup sour cream or full-fat, plain Greek yogurt

Preparation

1. Prepare the Graham Cracker Crumbs: In a medium skillet over medium heat, melt the butter. Add the crushed graham crackers, sugar, and salt.
2. Cook, stirring often, until the mixture is golden and fragrant, about 3 to 5 minutes.
3. Transfer to a plate to cool completely.
4. Make the Mousse: Using a stand mixer fitted with the whisk attachment, beat 1 cup of the cold heavy cream on medium-high speed until soft peaks form, 1 to 1 1/2 minutes. Transfer to a large bowl.
5. In the now-empty mixer bowl (no need to clean it), switch to the paddle attachment and beat the cream cheese and sweetened condensed milk on medium speed until smooth, about 1 minute.
6. Add the lime zest and lime juice, and beat until fully combined and creamy, about 1 more minute.
7. Add the sour cream (or Greek yogurt) and mix until smooth.
8. Gently fold the whipped cream into the lime mixture using a flexible spatula until fully incorporated.
9. Assemble and Chill: Spoon 2 Tablespoons of graham cracker crumbs into the bottom of each of 6 (8-ounce) glasses, jars, or ramekins. Reserve the remaining crumbs for garnish.
10. Divide the mousse evenly among the glasses (about a heaping 3/4 cup each). For smaller servings, use 12 (4-ounce) containers with 1 Tablespoon crumbs and a heaping 1/3 cup mousse each.
11. Cover and refrigerate for at least 2 hours, or up to 3 days.
12. Before Serving: Beat the remaining 2/3 cup cold heavy cream to soft peaks.
13. Dollop or pipe on top of each mousse cup.
14. Sprinkle with the reserved graham cracker crumbs and a pinch of lime zest for garnish.