Preheat oven to 400℉ and line a large baking sheet with parchment paper.
Trim the bottom of the Brussels Sprouts and slice each one in half from top to bottom.
Pat Brussels Sprouts dry with a paper towel. Place them in a large mixing bowl with olive oil, Italian seasoning, garlic, Parmesan, salt, and pepper. Toss gently but well.
Place Brussels Sprouts on baking sheet flat-side down in a single layer. Bake for 25-30 minutes until golden brown.