Mix the flour blend, xanthan gum, baking powder, and salt in a medium bowl until well combined.

Cut the butter in with a pastry cutter or flatten it between your fingers as you mix it with the flour. Ensure that the butter is evenly coated and mixed. 

Add the sour cream and combine until the mixture begins to form a dough ball. Add ice water a teaspoon at a time if necessary just to bring the dough together.

Remove the dough from the bowl, form into a ball, and wrap with plastic wrap. Place in the refrigerator for at least 30 minutes before rolling.

Remove the dough from the fridge and place on a lightly floured surface. Carefully begin to roll the dough with light pressure. 

Roll into a 12-inch circle that's between 1/4-1/2 inch thick. Carefully roll part of the dough onto the rolling pin and move the crust into the pie dish. (Our dough falls apart, but it's easy to put back together and bakes beautifully.)

Crimp or style the edges as desired. Poke holes in the bottom of the crust with a fork. Place parchment paper onto the crust and lay pie weights on the parchment paper.

Combine all ingredients in a medium bowl and pour into a cooled pie crust.

Bake at 350 for 10-15 minutes or until small bubbles form around the edge.

Remove from the oven and allow the pie to cool for about an hour before transferring it to the refrigerator to cool completely (2-3 hours).

Garnish with whipped cream of your choice.