Combine graham cracker crumbs with melted butter in a mixing bowl, and stir until the crumbs are evenly coated and resemble wet sand.
Press the crumb mixture firmly into the bottom and up the sides of a 9-inch pie pan, creating an even crust. Chill in the refrigerator for at least 15 minutes to firm up.
In a separate bowl, whisk the egg yolks until smooth and slightly pale, then strain if desired for extra silky texture.
Slowly pour the sweetened condensed milk into the yolks while whisking continuously, until fully combined and smooth.
Stir in the freshly squeezed lime juice gradually, tasting as you go to achieve the desired tartness. The mixture will thicken slightly and become silky.
Pour the lime filling into the chilled crust, spreading it evenly with a spatula. Smooth the top for a neat appearance.
Bake the pie in a preheated 350°F (175°C) oven for about 15 minutes, or until the filling is just set around the edges but still slightly jiggly in the center.
Remove the pie from the oven and let it cool to room temperature, then refrigerate for at least 2 hours or until fully chilled and set.
If desired, top with whipped cream before serving to add a light, fluffy finish.
Slice the pie with a sharp knife, and enjoy the satisfying crunch of the crust combined with the bright, tangy filling.
