Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
In a large mixing bowl, combine the gluten-free flour, sugar, baking powder, and salt. Whisk together.
In a separate bowl, whisk together the buttermilk, egg, and vanilla extract until fully combined.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Gently fold in the blueberries and lemon zest.
Turn the dough out onto a floured surface, shape into a circle about 1 inch thick, and cut into 8 wedges.
Place the wedges on the baking sheet, sprinkle with coarse sugar, and bake for 15-20 minutes until golden brown.
Let the scones cool on the baking sheet for a few minutes before transferring to a wire rack.