For the crust, combine the graham cracker crumbs, sugar, and butter and press into an 8'' square baking pan.
Bake at 350 degrees F for 10 minutes. Allow to cool before adding filling.
Add cream cheese to a mixing bowl and beat well with electric beaters until smooth. Add both cans of sweetened condensed milk, lime juice, and lime zest and mix again until smooth.
Pour over prepared graham cracker crust and bake in preheated oven for 10 minutes. Allow to cool for about 30 minutes, then refrigerate for at least 3 hours, before serving.
Top with fresh whipped cream, if desired.
Video
Notes
Lime Juice: There are 2 ways you can get key lime juice for this recipe. Juice about 20 of your own small key limes, OR I always use Nellie and Joe's Key Lime Juice (available at most grocery stores) in the bottle.Make Ahead Instructions: prepare and bake the pie up to 3 days in advance, stored in the refrigerator. The filling and crust can both be prepared separately, in advance, and then assembled and baked when ready. Freezing Instructions: Baked Key Lime Pie can be frozen for up to 3 months. Thaw overnight in the refrigerator before serving.