Preheat the oven to 425F and line a large rimmed baking sheet with foil.

Toss the Brussels sprouts with the olive oil, salt and pepper, then spread them cut-side down in a single layer; use two sheets if they are crowded.

Scatter the chopped bacon over and around the sprouts.

Roast for 20 to 25 minutes, without stirring, until the cut sides are deeply browned and the bacon is crisp.

Meanwhile, simmer the balsamic vinegar and honey in a small saucepan over medium heat for 3 to 4 minutes, until it reduces to a syrup that coats a spoon.

Transfer the sprouts and bacon to a serving bowl.

Drizzle with the balsamic syrup and toss once, gently, right before serving.