Preheat the oven to 400°.
Wash your brussels sprouts and pat them dry. Cut the ends off and then remove any damaged outer leaves. Cut the brussels sprouts in half.
In a mixing bowl, whisk together olive oil, vinegar, honey and mustard. Add the brussels sprouts and gently mix to coat them well.
Transfer the brussels sprouts to a parchment-lined baking pan. Keep in mind that the under side of the brussels sprouts will be the side that blackens. So, if you want a blackened round side, place them with the flat side up. If you want a blackened flat side, place them flat side down.
Bake in the oven for 20 to 25 minutes. Once they've cooked thoroughly and the undersides are blackened, removed them from the oven and let them cool for about 5 minutes before transferring them to a serving tray.
Garnish with optional glazed bacon bits and/or balsamic glaze.