Toss butternut squash and brussels sprouts in olive oil until coated. Place on a greased sheet pan and sprinkle with pepper and cinnamon.
Using a separate greased pan, toast the walnuts for 5 minutes or until slightly darker in color. Be careful to not overcook them as they easily burn. Set aside.
Bake the brussels sprouts and butternut squash for 25-30 minutes or until golden brown, flipping halfway through.
Add walnuts and maple syrup to the pan and toss until thoroughly mixed. Use more cinnamon if desired and serve warm.