Dice butter into small cubes. Place back in the refrigerator.

Place flour, cocoa, sugar, and salt in a food processor. Pulse a few times to combine.

Add the cold diced butter into the food processor. Pulse a few times until the butter is worked into the flour mixture.

Add 1 tablespoon of ice water. Let the food processor run for several seconds, until the dough becomes crumbly. If the dough seems too dry, add 1/2 teaspoon water and pulse a few more times. You can add another 1/2 teaspoon of water as needed. Just make sure it’s not too wet! The dough should be pinchable, but not dry or wet.

Pour crumbly dough into a 9” pie plate. Use your fingers to presss across the bottom and up the sides. Chill for at least one hour (or freeze for 10-15 minutes) before baking.

If making a baked pie shell for an unbaked filling: poke the very cold crust with the tines of a fork all over the bottom and sides. Bake at 400°F for about 8-10 minutes. Cool, then fill as directed.

If making a baked pie, fill chilled pie crust as directed and bake as the recipe directs.