1) Preheat oven to 450 degrees F. In a medium bowl, whisk together flour, cornmeal, brown sugar, baking powder, baking soda, and salt. Cut chilled butter into cubes and then mix the butter into the dry ingredients using your fingers until it’s in large pea-sized pieces.
2) In a separate bowl, whisk together milk, egg, and maple syrup.
3) Rinse blueberries and toss them with the corn starch.
4) Stir wet ingredients into the dry ingredients. Try not to over-mix the batter. Then fold in the blueberries.
5) Drop batter onto a baking sheet lined with parchment paper. I would shoot for scant quarter cup scones. You should get 8-12 scones out of the batch.
6) Bake scones at 450 degrees F. for 13-15 minutes until they are slightly puffed and golden brown.
7) Meanwhile whisk together powdered sugar and lime juice. When scones are done, let them cool and then drizzle with the icing. Serve immediately or store in an air-tight container (once cool) for a few days.