Spray a 10-inch pie plate with cooking spray. In a food processor, pulse the graham cracker crumbs until fine. Combine the crumbs with melted butter, sugar, and a pinch of salt in a mixing bowl. Press the mixture firmly into the bottom and up the sides of the pie plate. Place it in the freezer for 10 minutes to set.

In a large mixing bowl, beat the softened cream cheese with a hand mixer on medium speed until smooth. Gradually add the sweetened condensed milk, fresh lime juice, and lime zest, mixing until fully combined. Gently fold in the Cool Whip until the mixture is light and airy.

Once your crust has chilled, pour the lime filling into the prepared crust. Use a spatula to smooth the top evenly. Cover the pie with plastic wrap and place it in the refrigerator to chill for at least 4 hours or overnight.

After the pie has set, remove it from the refrigerator. Garnish the top with whipped cream, lime zest, and lime slices. Slice into wedges and serve chilled.