Preheat oven to 350F.
In a food processor quickly pulse the flour, powdered sugar, baking powder, and salt together.
Add in the cold butter cubes and keep pulsing until you get a coarse meal texture, about 6 pulses. It’s ok if you have a few pea size chunks of butter covered in flour.
Add in the egg and vanilla extract, pulse until a smooth dough forms.
Empty dough onto a very lightly floured large piece of parchment paper. Flatten the dough into a disk with your hands.
Cover the dough disk with another large piece of parchment paper which has the side facing the dough lightly floured.
Use a rolling pin to roll the dough out between the two pieces of parchment until the dough is ¼” to an 1/8” thick and at least a little over an inch wider than your tart pan on all sides. The floured parchment pieces should not stick too strongly to the dough, you can add more flour if necessary.
Remove one of the parchment pieces and transfer the dough carefully into a 9” fluted tart pan with the dough touching the pan and the last piece of parchment laying on top. Gently remove this last piece of parchment and gently press the dough into the pan making sure the bottom edge and side edges are pressed in gently.
Remove the excess dough on the top by rolling the rolling pin over the edges.
You can use a fork to dock the bottom of the tart shell all over if you want which helps to prevent the centre from rising during baking.
Scrunch up a piece of parchment paper then unscrunch it and place in the tart shell. Fill the tart with pie weights or dry rice, or dry beans (see note 1). Place in the oven and bake for 20 minutes, remove beads and bake another 5-10 minutes until lightly browned.
Remove from the oven and allow to cool on a cooling rack