Blueberry Cornmeal Cobbler - The Local Palate

Ingredients

• 6 cups blueberries
• ⅔ cup sugar
• 1/3 cup tapioca starch
• 1 teaspoon freshly squeezed lemon juice
• ¾ teaspoon kosher salt
• 2 cups flour
• 1 ⅔ cups cornmeal
• ½ cup sugar
• 1 tablespoon plus 1 teaspoon baking powder
• ½ teaspoon baking soda
• 1 teaspoon salt
• ¾ cup unsalted butter, cut into 1⁄2-inch cubes and chilled
• 1 ⅔ cups buttermilk
• 1 large egg
• Demerara sugar for sprinkling