Step 1

Preheat the oven to 375 degrees F.

Step 2

In a small bowl, mix together the graham cracker crumbs, granulated sugar, and butter.

Step 3

Press the mixture into a pie pan and bake for 7 minutes.

Step 4

Cool the pie pan for 30 minutes.

Step 5

Preheat the oven to 350 degrees F.

Step 6

In a medium bowl, whisk together the sweetened condensed milk, sour cream, lime juice, and lime zest.

Step 7

Pour the mixture into the crust and bake for 10 minutes.

Step 8

Allow the pie to cool and chill for 3 hours in the fridge.

Step 9

When the pie has completed chilling, beat the heavy cream and powdered sugar together until stiff peaks form, using a mixer to assist.

Step 10

Beat in the vanilla.

Step 11

Spread the whipped cream atop the pie and add more lime zest.

Step 12

Serve!