Gluten-Free Pie Crust

Cut the cream cheese and butter into 1/2-inch pieces, place in a bowl, and freeze for 15 minutes. Use a coffee or spice grinder or mortar and pestle to grind the psyllium, flax and chia seeds to a fine powder. Transfer to the bowl of a food processor along with the salt, baking powder, and flour. Pulse a few times to combine.
Add the butter and cream cheese and pulse until the texture of the crumbs resembles sand, about 20 seconds. While pulsing the food processor, add vinegar and then 3 tablespoons ice water. Squeeze a small amount of dough between your fingers; if it is very crumbly, add more ice water, 1 tablespoon at a time (2 tablespoons maximum). Do not over process.
Turn the dough out onto a piece of plastic wrap, and gather into a ball with your hands. Knead the dough a few times to create a uniform texture. Divide the dough in half and form each piece into a flat disk about 1 inch thick. Wrap each half tightly in plastic and refrigerate until dough is chilled and stiff, at least 30 minutes (or up to overnight). Roll, fill, and bake as desired.
DO AHEAD: Dough can be frozen for up to 3 months; thaw in refrigerator before using.