Combine the butter and sugar in a food processor and pulse until they blend together, creating a paste-like mixture. Add the egg and vanilla, and pulse again to blend.
Incorporate the flour into the mixture and pulse until you achieve a smooth dough.
Transfer the dough to a surface lightly dusted with flour, shaping it into a disc. Wrap it in plastic wrap and refrigerate it for a minimum of 90 minutes.
Roll out the chilled dough between two sheets of parchment paper, creating a circle with a diameter of 9.5 inches. Carefully remove the top parchment paper (if the dough is too soft, refrigerate it for 15 minutes to firm up).
Using the bottom parchment paper, gently lift the dough and place it over the tart shell (with the parchment paper facing up). Press the dough into the pan with your fingers to ensure there are no gaps between the pan and the dough. Return the pan with the dough and parchment paper to the refrigerator for an additional 20-30 minutes to set.
When ready to bake preheat oven to 375F (190C).
Remove the parchment paper from the chilled dough and use a knife to trim any access dough.
Use a fork to prick the dough, line it with parchment paper, and top it with pie weights or dry beans.
Bake over the lower oven shelf for 30 minutes. Allow to cool before removing the weights.