Blueberry Molasses Cake

1 cup plus 2 tablespoons unbleached all-purpose flour 1 teaspoon baking powder 1/2 teaspoon baking soda 3/4 teaspoon salt 1/2 teaspoon cider vinegar 5 tablespoons milk (divided) 1/2 cup unsulphered molasses 2 large eggs, lightly beaten 3 tablespoons unsalted butter, barely Read on!