In a 9x9 square baking dish, combine the frozen blueberries, lemon juice, zest, and coconut sugar and stir to combine. Set aside while you make the topping.
Add the cassava flour, coconut sugar, cinnamon, ginger, and salt to the bowl of a food processor and pulse to combine.
Add the shortening to the bowl of your food processor in large clumps. Sprinkle in the vanilla. Lock the lid and pulse off and on, gently, until shortening is dispersed into large granules. Do not over-mix. While pulsing gently, add the ice water to the bowl of your food processor and continue to process until the granules are pea-sized or smaller. Again, do not over-mix, or you will end up with a dough. Your mixture should be dry and crumbly.
Top the blueberry mixture with the crumble mixture, using a spatula to spread out evenly. Bake for 45 minutes, or until topping is browned. Allow to cool at least 15 minutes before serving.
Recipe by Autoimmune Wellness at https://autoimmunewellness.com/blueberry-crumble/