Preheat the oven to 425°F. Line a baking sheet with aluminum foil and spray with cooking spray.

Add the Brussels sprouts to the prepared baking sheet. In a medium bowl, whisk together the olive oil, balsamic vinegar, brown sugar, mustard, and orange juice. Pour about ½ cup of the glaze evenly over the Brussels sprouts, sprinkle with salt and pepper, and toss to coat.

Arrange the Brussels sprouts cut-side down and roast until they begin to turn golden, about 20 to 25 minutes. Stir and return to the oven to bake until tender and caramelized, about 10 to 15 minutes more.

Drizzle the Brussels sprouts with the remaining glaze and toss before serving.