Step 1

Preheat the oven to 350 degrees Fahrenheit (175°). Line an 8x8-inch baking pan with parchment paper or foil, leaving an overhang on the sides. Spray with cooking spray and set aside.

Step 2

Make the crust: Mix the graham cracker crumbs, sugar, and melted butter until well combined. Press the mixture evenly into the bottom of the prepared pan and bake for 10 minutes. Reduce the oven heat to 300°F (150°C) and set the crust aside to cool.

Step 3

Make the filling: In a large bowl, beat the cream cheese with an electric mixer on medium until smooth. Scrape the bottom and sides of the bowl, then blend in the yolks.

Step 4

With the mixer on low, add the sweetened condensed milk, key lime juice, and lime zest and blend until fully incorporated.

Step 5

Pour the filling over the crust and spread into an even layer. Bake for 35-40 minutes or until the filling is slightly jiggly but set. Let the bars cool at room temperature for 30 minutes, then refrigerate for at least 2-3 hours to fully set.

Step 6

Make the topping: Beat the heavy cream and powdered sugar on low until thick, then increase the speed to medium-high and whip to stiff peaks. Spread evenly over the key lime bars and chill for 30 minutes.

Step 7

Once chilled, use the parchment overhang to carefully lift the bars out of the pan. Cut them into squares with a sharp chef’s knife, sprinkle with lime zest, and enjoy!