Preheat your oven to 350°F (175°C). Allow at least 10 minutes for the oven to reach the desired heat.

In a mixing bowl, combine all-purpose flour, granulated sugar, softened unsalted butter, and a pinch of salt. Blend until it resembles coarse crumbs, about 5 minutes. Press this mixture into the bottom of a greased square baking dish.

Place the pressed crust in the oven and bake for 15-20 minutes until golden brown. Let it cool slightly while preparing the custard.

In a saucepan over medium heat, combine milk, granulated sugar, and cornstarch. Stir continuously until thickened, about 5-7 minutes.

Whisk egg yolks and vanilla extract in a separate bowl. Slowly pour the hot milk mixture into egg yolks while whisking constantly to combine.

Return the custard mixture to the saucepan and cook over medium-low heat for an additional 2-3 minutes until thickened to pudding-like consistency. Remove from heat and let cool for a few minutes.

Pour the thickened custard over the warm baked crust, spreading evenly. Allow to cool at room temperature for about 30 minutes before refrigerating for at least 2 hours.

Once chilled and set, slice into squares using a knife dipped in hot water, and serve chilled.