Dressing

Cut vanilla bean lengthwise in half and scrape out seeds with a small knife. Put bean pod and seeds into a small saucepan with balsamic vinegar. Gently steep mixture until barely simmering. Let cool and strain to remove pod and seeds. Add honey, then whisk in olive oil. Season with salt and pepper to taste.
Salad

Preheat oven to 400 degrees. Toast hazelnuts 3 to 6 minutes or until just lightly golden. Toss warm hazelnuts with oil and salt. Hull strawberries and cut in quarters. In a large bowl, gently toss baby spinach, strawberries and hazelnuts together. Stir dressing, then add to salad before serving.