Step 1

In a large bowl, place the flour, xanthan gum, baking powder and salt, and whisk to combine well. Add the chopped and chilled butter, and toss to coat it in the dry ingredients.

Step 2

Flatten each chunk of butter between your thumb and forefinger to make flat shards of butter, coated fully in flour.

Step 3

Create a well in the center of the dry ingredients with the butter shards, add the sour cream, and mix to moisten the dry ingredients with the sour cream. The dough should be shaggy and somewhat crumbly.

Step 4

Knead the dough together with clean hands until it begins to come together. Add ice water by the teaspoon only if necessary for the dough to hold together.

Step 5

Turn the dough out onto a sheet of plastic wrap, and press into a disk as you close the plastic wrap around the dough. It will still seem rough. Place the dough in the refrigerator to chill for 30 minutes.

Step 6

Preheat your oven to 375°F. Grease a 9-inch metal pie plate generously and set aside.

Step 7

Once the dough has chilled, turn it out onto a lightly floured piece of unbleached parchment paper. Sprinkle the dough lightly with more flour, and roll it out into a rectangle that is about 1 inch thick, moving the dough frequently and sprinkling it lightly with flour if it begins to stick.

Step 8

Fold the dough over on itself like you would a business letter. Sprinkle the dough again lightly with flour, and roll out the dough once again into a rectangle about 1 inch thick.

Step 9

Twice more, remove the top piece of parchment paper, sprinkle lightly with flour, and fold the dough over on itself like you would a business letter.

Step 10

Roll out the dough into an approximately 12-inch round, about 3/8-inch thick. Roll the pie crust loosely onto the rolling pin and then unroll it over the prepared pie plate.

Step 11

Trim the roughest edges of the crust with kitchen shears. Lift up the edges of the pie crust gently to create slack in the crust, and place the crust into the bottom and up the sides of the pie plate.

Step 12

Tuck the excess pie crust under itself, and crimp the edge gently all the way around the crust by pinching the dough at regular intervals with one hand, and creating a crimped impression with the forefinger of the other hand. Cover the pie crust with plastic wrap and place it in the refrigerator to chill until firm, at least 30 minutes (and up to 3 days).

Step 13

Remove the pie crust from the refrigerator and unwrap and discard the plastic. Pierce the bottom of the pie crust all over with the tines of a fork.

Step 14

Place a sheet of parchment paper on top of the raw crust and cover the bottom of the crust with pie weights or dried beans.

Step 15

Place in the center of the preheated oven and bake until the crust is lightly golden brown on the edges, about 10 minutes.

Step 16

Remove the pie weights and parchment and allow the crust to cool before proceeding with your recipe.