Season the rabbit with the salt. Heat the oil in a large skillet over medium heat. Cook the rabbit until browned on all sides, about 6 minutes per side. Transfer to a plate. Add the onions, sage and mint and cook until tender, about 3-5 minutes. Add the cider and stock and scape up any dark bites sticking to the bottom of the pan.
Return the rabbit to the pan, then add the maple syrup and vinegar. Cover the pan and braise until tender, about 45 minutes to 1 hour, turning pieces occasionally. Uncover, add the apples and continue cooking, basting the rabbit until the sauce is thickened.