Preheat oven to 450 degrees.
Place butter in a small saucepan and carefully heat over medium heat until the butter is melted, browned and fragrant, about 3 to 5 minutes.
In a large bowl, toss Brussels sprouts and hazelnuts with the browned butter, salt and pepper. Place Brussels sprouts mixture in a single layer on a nonstick sheet pan (or sheet pan lined with foil or a nonstick baking mat.)
Place in oven and roast for 10 minutes. Check for doneness. Sprouts should be tender but not mushy. Continue roasting a few minutes more if necessary.
Remove from oven and toss in a large bowl with lemon rind. Serve immediately.