Step 1Combine flour, sugar and salt in bowl of standing mixer. Cut butter into 1/2-inch cubes and add to flour mixture. On slow speed, mix butter and flour until texture resembles coarse oatmeal.
Step 2Beat egg and vanilla together in small bowl and add to flour mixture. Mix until dough pulls together. Form 2 thick flat disks and set aside to rest 5 minutes.
Step 3Roll out dough disks slightly thinner than 1/4-inch thick and cut out circle 2 inches larger than your tart pan. Ease dough into tart pan and press firmly into pan. Chill 1 hour. Line shell with foil and fill with baking weights.
Step 4Bake at 375 degrees 20 minutes then remove foil and weights and return shell to oven until edges are lightly golden and center is no longer wet looking, 8 to 10 minutes more. (Small individual tartlets may be baked without foil and weights and take 15 to 20 minutes depending on size.)