In a large mixing bowl, combine the gluten-free flour, xanthan gum (if needed), sugar, and salt.
Add the cubed cold unsalted butter to the flour mixture. Using a pastry cutter or your fingertips, work the butter into the flour until it resembles coarse crumbs.
Gradually add the cold water to the mixture, stirring with a fork until the dough begins to come together.
Turn the dough out onto a lightly floured work surface and gently knead it until it forms a smooth ball.
Flatten the dough into a rectangle, then wrap it tightly in plastic wrap and refrigerate for at least 30 minutes.
Once chilled, remove the dough from the refrigerator and place it on a floured surface.
Roll the dough out into a large rectangle, about 1/4 inch thick.
Arrange the cold unsalted butter cut into thin slices evenly over two-thirds of the dough, leaving one-third of the dough without butter.
Fold the unbuttered third of the dough over the middle third.
Then, fold the remaining third over the top to create three layers.
Rotate the dough 90 degrees, then roll it out into another large rectangle.
Repeat the folding process by folding one third over the middle.
Finally, fold the remaining third over once again to create three layers.
Roll out the dough into a large rectangle again.
Wrap the dough tightly in plastic wrap and refrigerate for at least 30 minutes before using in your desired recipe. (I sliced mine into squares to make little pastries).
Video
Notes
*Use a high-quality, all-purpose gluten-free flour blend. Don't substitute the all-purpose blend with coconut flour or almond flour—they won't give the same results.*Your butter must be cold. Chill it in the refrigerator before using. I cut my butter into two shapes: small cubes and thin slices. The cubes are cut into the dry ingredients, while the slices are layered in the first fold during the 'lamination' process.
Don't overwork the dough; otherwise, the butter will soften, and the pastry won't puff up in the oven.