Makes 2 tart shells
8 tablespoons unsalted butter, softened
1 1/3 cups powdered sugar
1 teaspoon salt
1 3/4 cup all-purpose flour
Cream together butter and sugar until very light and fluffy. Add egg and salt and continue mixing until combined. Stir in flour with a large spoon, by hand, just until dough is formed. Wrap in plastic wrap and refrigerate 2 to 3 hours or overnight.