Beat 1 cup dark brown sugar and 1 stick butter until fluffy, then beat in 3 egg, 1 teaspoon vanilla, 4 ounces melted semisweet chocolate and 2 tablespoons buttermilk with the eggs. Whisk 1 1/2 cups flour, 1/2 cup Dutch-process cocoa powder, 3/4 teaspoon salt and 1/4 teaspoon baking powder; stir into the butter mixture. Add 2 cups chocolate chunks and 1 cup dried cherries to the finished batter. Drop by tablespoonfuls and chill 30 minutes; bake 8 to 12 minutes at 350 degrees.