In a food processor, combine the flour, sugar, and salt. Add the cold butter cubes and pulse until the mixture resembles coarse crumbs.

Add the egg yolk and pulse until combined.

Gradually add ice water, 1 tablespoon at a time, pulsing until the dough starts to come together.

Turn the dough onto a lightly floured surface and shape it into a disk. Wrap it in plastic wrap and refrigerate for at least 30 minutes.

Preheat your oven to 375°F (190°C).

Roll out the chilled dough on a lightly floured surface to fit a 9-inch tart pan with a removable bottom.

Press the dough into the tart pan, trim any excess, and prick the bottom with a fork.

Line the tart shell with parchment paper and fill with pie weights or dried beans.

Bake for 15 minutes, remove the weights and parchment, and bake for an additional 10 minutes, or until the crust is golden brown.

Allow the tart shell to cool completely.

In a saucepan, heat the heavy cream and the vanilla bean (split and seeds scraped) over medium heat until it just starts to simmer. Remove from heat and let it sit for 15 minutes to infuse the vanilla flavor. If using vanilla extract, add it after removing the cream from the heat.

In a bowl, whisk together the egg yolks, sugar, and salt until the mixture is pale and thick.

Slowly pour the warm cream into the egg yolk mixture, whisking constantly to prevent curdling.

Strain the mixture through a fine-mesh sieve into a clean bowl