Old-Fashioned Blackberry Cobbler

Ingredients:

4 cups fresh or frozen  blackberries
1 cup sugar (plus 2 tablespoons for topping)
1 tablespoon lemon  juice
1 cup all-purpose  flour
2 teaspoons baking powder
¼ teaspoon salt
1 cup milk
½ cup (1 stick) butter, melted

Instructions: