In a stand mixer fitted with a paddle attachment or a large food processor, combine the flour, sugar, and salt.
Add the diced butter and mix on low until the butter is blended in with no pieces larger than the size of a pea. Slowly add the cold water just until the dough comes together.
Form the dough into a flattened disc, wrap in plastic, and refrigerate for 30 minutes or up to 2 days.
Preheat oven to 400˚F. Grease a 9 inch pie or tart pan with butter and dust with flour.
On a lightly floured surface, roll the refrigerated dough into an even, thin circle about 12 inches wide. Transfer to the prepared pie pan and decorate the edges as desired. Refrigerate until filling comes together.