In a large bowl, combine almond flour, granular sweetener, coconut flour, xanthan gum, kosher salt and baking powder. Use a pastry cutter or whisk to mix ingredients together well until there are no lumps. Alternatively, you can pulse in a food processor until combined.
Add apple cider vinegar, vanilla extract and cold butter chunks to the mixture. Cut the butter into the dough with the pastry cutter or by pulsing in the food processor until the dough forms a wet sandy texture. Don't over-mix. Add in egg, and mix until just combined.
Shape the dough into a ball shape, then cut the dough into two pieces. One piece should be slightly larger than the other, the larger piece will be for the bottom crust. This will be roughly a 60/40 ratio. Press to flatten each piece of dough into a round on plastic wrap. Wrap tightly with plastic wrap, and then freeze for 20 - 30 minutes, or refrigerate for 1 hour.
After the dough has chilled, place between two pieces of parchment paper, and roll the larger portion of dough into a circle that is a few inches in diameter larger than your skillet. Chill the rolled out dough in the fridge or freezer on a baking sheet for an additional 15 minutes to help stiffen the dough.
After dough has chilled, flip the chilled dough into a lightly greased pie pan. Don’t be alarmed that the edges of the dough will fall off and crack. This is normal since the dough is so delicate. Use the extra pieces of dough to patch any cracks in the pie crust and fill the sides of the skillet with dough using your hands. It doesn’t need to be perfect. Once you are happy with the look of your dough, set your pie pan in the fridge for 15 minutes to chill while you preheat the oven to 400°F.
After the dough is chilled for the final time, add a piece of parchment to the center and fill with pie weights to help keep it from rising too much. Bake for 10 minutes, then remove the pie weights. Keep a close eye on the crust, as it will brown quickly since it is made from almond flour. If you notice your crust browning too much, simply cover it with aluminum foil or a pie shield.
Return to the oven for an additional 10-15 minutes without pie weights, but with the edges covered until the center is golden brown. Remove from the oven and cool. Make sure to cool completely before adding a filling that is chilled and doesn't need to be baked. If your pie filling needs to be baked, be sure to cover the edges with foil again to prevent more browning. Continue on to pie top directions if baking further and you'd like a crust to top your pie.