To make the crust, combine the flour, powdered sugar and salt together. Add in the cubes of butter and use a fork or pastry cutter to cut the butter into the dough until it starts to appear like coarse sand (should still see small clumps of butter). Add in the ice water one tablespoon at a time, using your hands or a pastry cutter to bring the dough together. Only add as much water as you need to form the dough. The less water you add the better.
When the dough comes together in your hands and still has specks of butter, begin shaping it into a disk, wrap in cling wrap then refrigerate for at least 30 minutes.*
Once the dough has chilled, place a sheet of parchment paper on your work surface and lightly dust with flour. Position the dough at the center then place another sheet of parchment on top. Begin rolling the pastry until it is 10" in diameter and ⅛" thick. Gently transfer the pastry to your tart pan, lightly pressing it into the corners. Trim off any excess pastry and prick the base and sides with a fork. If any tears form, patch it up with leftover pieces of dough. Place the pan in the freezer for 15 minutes to chill the pastry.
Meanwhile, preheat the oven to 400°F (200°C) and prepare your baking beans and a glass bowl where you can place your hot beans in later. Line the chilled tart crust with parchment paper large enough to cover the tart while including some overhang. Fill it with the baking beans, spreading it to the corners and up the sides. Bake for 20 minutes.
Reduce the heat to 350°F (180°) then use the parchment paper overhang to remove the beans. Continue to bake the crust, uncovered, for 10-15 minutes or until the base starts to firm up and develop some browning.