Preheat oven to 375. Line a roasting pan with aluminum foil or parchment paper
In a saucepan, reduce apple cider to a syrup consistency and then set aside. Add mustard, brown butter, and maple syrup.
ln a bowl, add olive oil, Awesome Antler rub, and carrots. Toss to coat.
Transfer the carrots to the roasting pan; spread carrots a single layer, and roast for about 30 to 40 minutes. Stir a few times every so often so they roast evenly.
Drizzle the glaze over carrots and roast for another 15 to 20 minutes.