Add almond flour, coconut flour, xanthan gum, sweetener, baking powder and salt to the food processor and pulse until evenly combined.  Add butter, sour cream, egg and vinegar and pulse for just a few seconds until the dough just begins to come together (but stop before it forms into a ball). The mixture ought to resemble coarse breadcrumbs rather than cookie dough.

Dump the dough from the food processor onto saran wrap and loosely shape into a round disk.  Refrigerate the dough for at least 2 hours, or up to 3 days. You can also freeze the pie crust until ready to use.  When ready to use, place the dough in the fridge overnight to thaw.  Either roll out the crust between parchment paper or simply press chunks of dough into a pie pan.  IF the dough gets too warm, it will begin to get very sticky.  If this happens, simply place the dough in the freezer for about 5 minutes.   Once the pie crust has been shaped, place the crust into the freezer for 10-15 minutes.  I usually turn on my oven at this point to begin preheating. Bake at 375 degrees F for 12-15 or until the bottom begins to brown.  IF the edges begin to brown before the pie has finished baking, place aluminum foil over the pie to prevent more browning.