Preheat your oven to 350 degrees Fahrenheit and grab your pie dish.

Mix together your cassava flour, tapioca, cinnamon, and salt in a medium size bowl.

Drop the butter into the dry ingredients and cut together with a pastry cutter until the batter resembles coarse crumbs.

Pour in your whisked egg and stir to combine with a wooden spoon. If you can, use your fingertips! Slowly add in your 1/4 cup water and work it into the mixture until it's not too sticky. You want to be able to touch it and not have dough stick onto your fingers. Form the dough into a ball.

Lay down a sheet of parchment and dust it with tapioca flour. Place the ball of dough in the middle, dust with more tapioca, and cover with a second sheet of parchment. Flatten it slightly into a disc, and then roll out the dough into a large circle about 1/4 of an inch thick.

Pull back the top sheet and place your pie dish upside down on top of the crust. Carefully turn both over and flip the crust on top of the pie plate. Don't worry if it rips -- you can fix it!

Remove the parchment and patch up any broken areas of the crust. Poke the bottom of the crust with a fork a few times and place in the oven for 15 minutes to blind bake.

While the crust bakes, make your filling by combining all of the ingredients in a medium bowl and mixing until smooth and combined.

After 15 minutes, remove the crust from the oven, pour the filling inside, and return to the oven for 50-60 minutes. The pie is done when a toothpick comes out clean about an inch from the edge.

Let come to room temperature before putting in the fridge for 4 hours or overnight before cutting to serve!

Serve with some cocowhip, because that's the best way!