Cut the cold butter into small cubes.
Add the einkorn flour, salt, and butter to a food processor fitted with an S blade. Pulse several times until flour and butter look like small peas. Don't over mix.
Sprinkle the mixture with 6 tablespoons of cold water and pulse for about 30 seconds or until the flour mixture comes together into a ball. Do not over mix. Add an extra tablespoon or two of water if it's not coming together.
Move the mixture to a work surface that is dusted with flour. Using your hands, quickly pack the dough into a ball (like you’re packing a snowball). Then flatten the ball into two 3/4-inch thick disks.
Wrap and chill the dough: Wrap the dough disks tightly in plastic wrap, then refrigerate (freeze the extra disk) for at least 30 minutes to 1 hour, until ready to roll out and use.
Once the dough has chilled, transfer the dough to a well-floured work surface. Unwrap and lightly dust the top of the dough and the rolling pin with flour. Then gently roll the dough into a circle that is at least 12 inches in diameter (the perfect size for a 9-inch pie plate). Carefully transfer the dough to the pie plate, and gently press the dough into the sides of the plate without stretching it. Use kitchen shears or a knife to trim off any excess pastry, leaving about a 1-inch border of crust around the top of the pie plate. Use your fingers to press the dough to form a scalloped edge, or create whatever other decorative crust design you prefer. Chill pie crust for at least 15 minutes while making the filling.