Combine first 6 ingredients in a small bowl; set aside.
Cut onions into quarters to, but not through, bottoms. Turn onions on sides, and thinly slice. Cover and cook onion in oil and butter in a large skillet over medium-low heat 15 minutes or until tender, stirring occasionally. Uncover and cook 30 minutes or until very tender, stirring often. Add raisin mixture and apple. Cook, uncovered, over medium heat 20 minutes or until liquid evaporates and apple is tender, stirring occasionally. Stir in salt and pepper. Let cool. Serve at room temperature.