In a food processor, add the flour, salt, and vanilla sugar. Pulse it to sift.
Add the cold butter and pulse a few times until the mixture looks like coarse crumbs.
Pour the water 1 tablespoon at a time and pulse until the mixture just forms a dough.
Put the dough in a plastic wrap. Press the dough into a flat disc and refrigerate at least 30 minutes before rolling out.
When it is ready to use. Butter a tart pan (11 inches). Precisely fit it in a tart pan (11 inches). Poke the dough all over with a fork. Then put the pie back into the fridge to harden.
Preheat the oven to 350 F. When it is hot, remove the pie from the fridge. Put some parchment paper on the dough. Put some pie weights or dry beans to cover the entire bottom and angles of the pie well.
Cook for 20 minutes until the crust is lightly brown
Remove the pie from the oven. Pull out the parchment paper by holding the 4 corners and remove the pie weights or dry beans. Put them in a bowl to cool off (be careful not to burn yourself, they are very hot!) Let the pie crust cool down on a wire rack.