Prepare dough: Combine flour, powdered sugar, salt in food processor.
Add cold butter, pulse until pea-sized pieces form. Alternatively, mix by hand.
Mix in egg, vanilla until dough forms, avoid overmixing.
Chill dough: Wrap in plastic, refrigerate for at least 1 hour.
Roll out: On floured surface, roll into rectangle, cut rounds larger than tart pans.
Prepare shells: Press dough into tart pans, trim edges, dock with fork, freeze 20 mins.
Bake: Preheat oven to 180°C (350°F), bake shells 15-20 mins until golden, cool.
Make cream: Simmer milk, vanilla. Whisk sugar, cornstarch, yolks, ¼ cup milk; combine, thicken over low heat, chill.
Assemble: Pipe cream into shells, top with berries. Optional: glaze with apricot jam and water.