- 3 cups sweetened condensed milk
- ¾ cup key lime juice
- ½ cup sour cream
- 1 tablespoon grated lime zest
- 1 (9-inch) prepared graham cracker crust
- Preheat the oven to 350 F.
- Combine condensed milk, key lime juice, sour cream and lime zest in a bowl; mix well. Pour into graham cracker crust; place pie on a baking sheet.
- Bake in the preheated oven for 5 to 8 minutes, until tiny pinhole bubbles burst on the surface of the pie. The filling will be wobbly but not browned.
- Transfer pie to a wire rack to cool, then thoroughly chill pie in the refrigerator before serving, about 1 hour. Garnish with lime slices and whipped cream, if desired.