Preheat the oven to 400°F. Place the hazelnuts on a small baking sheet and bake for 10-15 minutes, or until the hazelnuts are toasted. Remove them from the oven and allow them to come to room temperature. Put them into a container that holds at least twice the volume of the hazelnuts, put a lid on it and shake vigorously to remove the husks. Separate out the hazelnuts.
In a small bowl, combine the balsamic vinegar, honey, orange zest, and dijon mustard. Drizzling slowly in the bowl, whisk in extra virgin olive oil until combined and emulsified. Season with salt and pepper and set aside.
Put the arugula, figs, red onion, and hazelnuts in a large bowl. Toss it with the balsamic-orange dressing. Garnish the fig with the prosciutto and crumbled goat cheese and serve.
Notes
To add some extra garnish and bring out the orange flavor, you can squirt the fresh orange juice into the balsamic vinaigrette, or directly onto the salad.