1 (9 inch) prepared graham cracker crust
2 cups sweetened condensed milk
1/2 cup sour cream
3/4 cup lime juice (about 4-5 Persian limes, depending on size)
1 teaspoon vanilla extract
1 tablespoon grated lime zest
1. Preheat oven to 350 degrees F (175 degrees C).
2. In a medium bowl, combine condensed milk, sour cream, vanilla, lime juice, and zest. Mix until batter is smooth and all ingredients are combined. Pour into graham cracker crust.
3. Bake in preheated oven for 15 minutes, until firm. DO NOT BROWN! Chill pie thoroughly before serving. Garnish with whipped cream if desired.