Place the cream cheese into a mixing bowl and use an electric mixer to blend until smooth and creamy. Add the sweetened condensed milk, lemon juice and lemon zest and blend again until the ingredients are fully incorporated and completely smooth.
Pour the filling into the pre-made graham cracker pie crust, smooth the top and chill in the refrigerator for 2 hours to set.
Top with whipped cream or cool whip and serve cold.
Video
Notes
Fat-free cream cheese can be used in place of full-fat cream cheese. The fat-free version gives this lemon icebox pie more of a sherbet taste and feel. Using fat free cream cheese and fat free condensed milk will bring the calories down to 187 per slice.
Make sure the cream cheese is at room temperature before mixing in order to get a smooth filling.
Bottled lemon juice can be used if you can't find fresh lemons. I tested the recipe with both options and my taste testers could NOT tell the difference.
Make this dessert up to 2 days ahead of time. Store covered in the refrigerator until you are ready to serve. This pie can be stored covered in the fridge for up to 5 days.