Preheat the oven to 350°F (175°C). In a mixing bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Press this mixture into the bottom and up the sides of a pie dish to form the crust.
In another bowl, whisk together sweetened condensed milk, egg yolks, lemon juice, lemon zest, and vanilla extract until smooth. Pour the filling into the prepared crust.
Chill the pie in the refrigerator for at least 2 hours to set.
Before serving, whip the heavy cream with powdered sugar and vanilla extract until soft peaks form. Spread the whipped cream over the pie and garnish with extra lemon zest.
Notes
For a firmer filling, you can bake the pie at 350°F (175°C) for about 10 minutes before chilling.
Keyword cream pie, dessert, Lemon Cream Pie, lemon pie