In a large bowl, whisk together flour and salt.

Cut in the cold butter using a pastry blender or your fingertips until the mixture resembles coarse crumbs with some pea-sized pieces of butter.

Gradually add ice water, 1 tablespoon at a time, mixing until the dough just comes together. Do not overmix.

Form the dough into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.

Preheat oven to 375°F (190°C).

On a lightly floured surface, roll out the dough into a 12-inch circle.

Carefully transfer the dough to a 9-inch pie plate. Trim and crimp the edges as desired.

Line the pie crust with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes.

Remove the parchment paper and weights, and bake for another 5-7 minutes, or until lightly golden. Set aside.

In a large bowl, whisk together the eggs, granulated sugar, cornstarch, and salt until smooth.

In a medium saucepan, heat the milk over medium heat until it just begins to simmer. Do not boil.

Gradually temper the egg mixture by slowly whisking about half of the hot milk into the egg mixture. This prevents the eggs from scrambling.

Pour the tempered egg mixture back into the saucepan with the remaining hot milk. Cook over medium-low heat, stirring constantly, until the custard thickens, about 5-8 minutes. It should be thick enough to coat the back of a spoon.

Remove from heat and stir in the vanilla extract and butter until the butter is melted and incorporated.

Pour the hot custard into the pre-baked pie crust.

Reduce oven temperature to 325°F (160°C).

Bake for 25-35 minutes, or until the center is just set but still has a slight jiggle.

Let the pie cool completely on a wire rack before refrigerating. For best results, chill for at least 4 hours or overnight.

Serve chilled. Optional: top with whipped cream or fresh fruit.