Place chicken livers in a colander and rinse with water. Drain and soak in milk for 30 minutes.
Make sauce. In a bowl, combine maple syrup, soy sauce and balsamic vinegar.
Rinse chicken livers with water again and drain well. Heat 1 tablespoon olive oil and cook chicken livers. When livers are cooked, add sauce and toss to coat. Reduce heat and add raisin, rosemary and butter. Stir well to coat. When butter is melted, season with salt and pepper. Turn off the heat and place on the serving plate.