blueberry cobbler recipe

Ingredients: 4 cups fresh blueberries 1 tablespoon lemon juice 1 cup sugar (divided) 1 cup all-purpose flour 1 teaspoon baking powder 1/4 teaspoon salt 1/2 cup milk 1/3 cup unsalted butter (melted) 1 teaspoon vanilla extract Optional: vanilla ice cream or whipped cream for serving