Preheat your oven to 350 degrees F. This is an essential step to ensure the crust cooks evenly.
In a medium bowl, whisk together the grated key lime zest and egg yolks for about 2 minutes until it becomes a bit fluffy. This step infuses the mixture with that amazing lime flavor.
Next, slowly whisk in the sweetened condensed milk until fully combined. You’ll want to see a smooth mixture without any lumps.
Add the fresh key lime juice and mix well. Allow this filling to sit at room temperature while you prepare the crust.
In another medium bowl, stir together the graham cracker crumbs, light brown sugar, and salt. Make sure there are no lumps of brown sugar, as this will affect the texture of your crust.
Drizzle the melted butter over the graham cracker mixture and use a fork to combine everything. The mixture should feel moist and crumbly.
Press this crust mixture firmly into the bottom and sides of a 9-inch pie plate. Make sure it’s tightly packed using the back of a measuring cup. This will ensure a sturdy crust.
Place the crust in the oven and bake for 10 minutes. This helps it firm up and adds a lovely golden color.
Once baked, transfer the crust to a wire rack to cool to room temperature. It’s important that the crust is cool before adding the filling.
Pour the lime filling into the cooled crust. Bake again until the center is set yet still wiggly, about 15 to 17 minutes. Keep an eye on it; you want it to be just right!
After baking, let the pie cool to room temperature. Once cooled, refrigerate it until well-chilled, at least 3 hours, or overnight for the best results.
For the whipped cream, use an electric mixer to whip the heavy cream on medium speed until soft peaks form. This step is crucial for achieving a light and fluffy texture.
Gradually add the powdered sugar, mixing continuously, then add the vanilla extract. Continue to whip until stiff peaks form.
Finally, decoratively pipe the whipped cream over the filling or spread it evenly with a spatula. Garnish with lime slices, if desired, and serve. Remember to cover any leftovers with plastic wrap and refrigerate for up to 3 days.
