Preheat oven to 375F/190C. Sift all-purpose flour through a fine mesh sieve into a large mixing bowl. (Optional to sift twice for extra light scones). Pulse oats in a blender, until finely ground, and add to bowl along with cane sugar, ground chia, baking powder, baking soda, sea salt and cardamom. Mix lightly to combine.
In a separate bowl combine coconut yogurt, almond milk and vanilla extract. Mix well.
Cut cold vegan butter into small cubes and add to dry ingredients. Massage with fingertips to combine the dough and butter, turning into a shaggy dough. Don't overwork the dough here, it should be shaggy and loosely combined. It's okay if it looks a little dry.
Slowly pour in liquid ingredients, while gently stirring to combine. Again, don't over mix. It's okay to be dry in places. Next add blueberries and mix gently to just combine.
Turn dough onto clean work surface and form together to make a round disk, about 1-inch thick. Optional to sprinkle the top with more flour if there are sticky spots while forming.
In a small bowl, whisk together almond milk and neutral oil. Paint the surface with liquid mixture to cover, and sprinkle with oats and cane sugar.
Line a baking tray with parchment paper. Using a spatula gently transfer scones to baking tray. Leave space between to allow them to grow. Bake for 20-25 minutes, or until golden.
For the glaze (optional): combine yogurt, lemon juice and agave. Drizzle scones with glaze and serve.