Preheat the oven to 350°F (175°C). In a mixing bowl, combine graham cracker crumbs, sugar, and melted butter. Mix until well combined.

Press the mixture into the bottom and up the sides of a 9-inch pie dish. Bake for 10 minutes, then remove and let cool.

In a mixing bowl, whisk together egg yolks and key lime juice until combined.

Add the sweetened condensed milk and whisk until smooth. Pour the filling into the cooled crust.

Bake the pie in the preheated oven for 10 minutes. Remove and let cool to room temperature, then refrigerate for at least 2 hours.

In a mixing bowl, beat the chilled heavy whipping cream, powdered sugar, and vanilla extract until soft peaks form.

Spread the whipped cream over the chilled pie before serving.