Maple Apple Raisin Oatmeal

• 3 and 1/2 cups milk
• 1/8 teaspoon salt
• 2 cups quick or old-fashioned oats
• 1 cup medium apple (cored and peeled) - finely chopped
• 1 Tablespoon butter
• 1/4 cup maple syrup
• 1/2 cup raisins
• 1/2 cup chopped nuts - optional