In a large bowl, mix vinegar, marmalade, and sesame oil. Add salt and pepper to taste. Add spinach, persimmons, and pecans. Mix gently to coat with dressing.
The dressing and persimmons for this salad can be prepared up to 4 hours ahead; wrap fruit airtight and chill. Assemble the salad shortly before serving. You'll find glazed pecans in the nut section of your supermarket.