In a saucepan over medium heat, stir together the vinegar, ketchup, soy sauce, and pineapple. Stir in brown sugar, cornstarch, salt, and ginger. Cook, stirring constantly, until slightly thickened, about 5 minutes.
Arrange a layer of spareribs in a roasting pan. Pour half of the sauce over the top. Arrange another layer of spareribs, and top with remaining sauce. Cover pan tightly with foil.
Bake in a preheated oven until done, about 1 1/2 to 2 hours.
