Preheat the oven to 400ºF or 200ºC.
Mix the plant milk and vinegar in a jar or bowl until well combined. Let the mixture rest at room temperature for at least 5 minutes. After this time, the milk will thicken and curdle.
Mix all the dry ingredients in a large mixing bowl (flour, sugar, baking powder, salt, and cinnamon) until well combined.
Grate the frozen vegan butter using a box grater. Add it to the mixing bowl and combine with a pastry cutter (you can also use your hands or even two forks) until the mixture comes together in pea-sized crumbs.
Incorporate the milk and vinegar mixture, the vanilla extract, and the blueberries, and mix until well combined.
Pour the dough onto the counter and work the dough into a ball with floured hands. It will be sticky, but if it's too sticky, add a little more flour. If your dough is too dry, add a little bit of plant milk. Press into an 8-inch disc (about 20 cm) cut into 8 wedges using a sharp knife.
Transfer to a lined baking sheet, brush the scones with some milk for extra crunch and refrigerate for at least 15 minutes.
Arrange the scones 2-3 inches apart onto the baking sheet (about 5-7 cm), and bake for 20-26 minutes or until lightly browned on top.
Let the scones cool for at least 15 minutes, then drizzle some of the glaze onto each scone.
Let the glaze set before serving your vegan scones.
Keep the leftovers at room temperature for 2-3 days, in the refrigerator for up to 1 week, or in the freezer for up to 3 months. Allow the scones to defrost at room temperature for 2-3 hours.