Combine the apples, spinach, endive, walnuts and blue cheese in a large bowl. Add the vinaigrette and toss to coat. Season with salt and pepper to taste.
Whisk together the pomegranate molasses, vinegar, mustard and honey in a medium bowl. Season with salt and pepper. Slowly whisk in the olive oil until emulsified. The dressing can be made 2 days in advance and stored in a container with a tight-fitting lid in the refrigerator.