To make crust, mix almond flour, tapioca flour and salt.
Grate cold butter using a cheese grater.
Using your hands mix in butter with flour.
In a separate bowl, crack the eggs and add vinegar. Whisk with a fork.
Add in icy water and pour into dry ingredients.
Mix until just incorporated and separate into two bowls. Wrap in cling wrap and place in the refrigerator until ready to roll.
In a large bowl, mix chopped rhubarb, raspberries, tapioca starch, coconut sugar and lemon juice.
Roll out dough on parchment paper until ¼ inch thick. Place one crust in pie plate.
Add in filling and roll out second pie crust to ¼ inch thick. Place over the top and flute the crusts together, removing excess crust. Brush with and egg white wash (egg white + splash of water) and bake for 45-60 minutes.
Recipe by Simple Roots at https://simplerootswellness.com/raspberry-rhubarb-grain-free-pie/