In a food processor, pulse gluten-free flour and coconut sugar for the crust. Add cold coconut oil and pulse until it resembles coarse sand with some oil chunks. Add egg yolk and apple cider vinegar, pulse. Gradually add ice water until dough forms. Chill dough for 30 minutes.
Roll chilled dough between parchment paper to ¼ inch thick. Transfer to a greased pie dish. Chilled in fridge while preparing filling.
Mix blueberries with coconut sugar, cinnamon, lemon juice, vanilla extract, gluten-free flour, and tapioca starch in a bowl. Add filling to pie shell.
Combine crumble ingredients in a bowl until crumbly. Sprinkle over filling.
Bake at 375°F (190°C) for 50-55 minutes, or until golden. Cool before serving.