In a small bowl, whisk together yolk, milk and vanilla.
In a food processor, combine flour, sugar and salt. Pulse for 5 seconds. Scatter butter cubes over top and pulse 12-15 times.
With processor running, add egg mixture and process until dough comes together--about 10-15 seconds.
Turn dough onto plastic wrap. Flatten into a 6 inch disk and wrap in plastic. Refrigerate 1 hour or up to 2 days--freeze up to 1 month. Remove dough from refrigerator 10 minutes before ready to roll out.
On a lightly floured surface, roll dough into an 11-inch circle. Place dough on baking sheet, cover with plastic and return to refrigerator for 30 minutes.
Remove dough from refrigerator and roll dough onto a 9-inch tart pan. Ease dough into pan and press into flutes and bottom of pan. Run the rolling pin over the top of the pan to remove excess dough. Wrap in plastic wrap and freeze for 30 minutes (or up to 1 month)
Preheat oven to 375 degrees. Place tart pan on rimmed baking sheet. Cover with foil sprayed with cooking spray, and fill with weights.
Bake for 25 minutes, rotating pan halfway through baking. Remove foil and weights and bake for 5 to 10 minutes more until tart is fully baked and golden brown. Cool on baking sheet on wire rack for 1 hour.