Preheat your oven to 350°F (175°C). In a bowl, combine graham cracker crumbs, ground pecans, melted butter, and powdered sugar until it resembles wet sand. Press this mixture into the bottom and up the sides of a springform pan. Bake for 10 minutes and cool.

Zest and juice your limes. In a bowl, whisk together lime zest, sweetened condensed milk, egg yolks, sour cream, lime juice, vanilla extract, and salt until smooth.

Pour the filling into the cooled crust and spread evenly. Bake at 350°F (175°C) for 20-25 minutes, or until the center jiggles slightly. Cool to room temperature and refrigerate for at least 4 hours.

In a food processor or bowl, whip the heavy cream, additional powdered sugar, vanilla extract, and salt until soft peaks form.

Spread the whipped cream over the chilled pie and garnish with lime zest and slices. Slice and serve.