In a bowl, whisk together flour, powdered sugar and salt. Set aside.
Work in butter and egg yolk with a pastry blender or with your fingers, until pea size pieces are formed.
Add ice water, one tablespoon at a time, until dough comes together.
Form dough into a disc. Wrap in plastic and refrigerate for one hour.
On a lightly floured surface, roll dough to a scant 1/4-inch thickness
Cut dough into six 5-inch rounds. Press rounds into six 4-inch or 4 1/4-inch tart pans.*
Dock the bottoms of pie crusts with a fork. Freeze for 30 minutes.
Heat oven to 375ºF. Place tart pans on a large baking sheet.
Line tart shells with six 6-inch parchment rounds. Fill with pie weights. (You can use dried beans or rice if you don't have pie weights.)
Bake tart shells for 12 minutes. Remove parchment paper and pie weights. Continue baking until tart shells are light golden brown, about 4-6 more minutes.
Transfer to cooling rack to cool completely.