Preheat oven to 375°F. Toast hazelnuts in a small shallow baking pan until golden, 4 to 5 minutes. Once cooled, finley chop. Trim woody ends from asparagus and place on a baking sheet. Drizzle asparagus with olive oil, and bake in oven for approximately 10 minutes, turning once. Whisk together remaining ingredients except nuts with salt and pepper to taste.
Transfer hot asparagus to plates. Spoon orange dressing over top and sprinkle with nuts.