Preheat oven to 400 degrees. Prepare brussel sprouts by washing, chopping off ends, removing any brown leaves and cutting in half; place in a large bowl along with the cubed butternut squash. Add the olive oil, maple syrup or honey, spicy mustard, salt and pepper and combine well.
Place the vegetables on a large sheet pan, lined with a silicone mat (or lined with foil/parchment paper and sprayed with oil). Roast in the oven for 25 minutes. While vegetables are cooking, slice each link of chicken sausage into 3 pieces.
After vegetables have cooked 25 minutes, remove pan from oven and toss veggies so they can brown on both sides. Then, snuggle the pieces of chicken sausage and return pan to oven for 10-15 minutes for the veggies and sausages to lightly brown and caramelize. Remove from oven and serve warm. If desired, serve with spicy mustard on the side for dipping (optional).