Preheat oven to 325 degrees F. Butter up a 12-inch skillet liberally. Whisk together the flour, sugar, blue cornmeal, baking powder and salt in a bowl. Whisk together the milk, vegetable oil, 6 tablespoonsmelted butter. Whisk the wet ingredients into dry ingredients. Fold in 1 pint of the blueberries. Pour batter into the skillet and top with the remaining pint of blueberries.
Bake until there is cracking on top and a skewer comes out clean, about 1 hour. Remove from the oven, poke multiple holes with the skewer and brush the remaining melted butter and let cool.