First, candy the hazelnuts. Preheat the oven to 350 degrees F. In a small bowl, whisk together the brown sugar and hot water. Add the hazelnuts and toss until well coated. Pour mixture onto a large baking sheet that has been lined with a Silpat baking mat or parchment paper. Bake until hazelnuts are crisp, about 12-15 minutes. Remove from oven and let cool. Once cooled, break hazelnuts apart. Roughly chop and set aside.
Preheat grill to medium heat. Place cherries in a medium bowl. Add 2 tablespoons of balsamic dressing and toss well. Place cherries on a grill pan and grill until tender, about 5 minutes. Use a spatula to turn occasionally while cooking.
In a large bowl, add greens, grilled cherries, blueberries, goat cheese, and candied hazelnuts. Drizzle with additional balsamic dressing and serve immediately.
Note-I usually don't add the full 1 cup of hazelnuts to the salad, but I like to candy 1 cup at a time. Add however many you like!