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 or measuring cup, 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 and sprinkle with salt and pepper. 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, another 10 to 15 minutes.

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