Preheat oven to 450˚F. Line a baking sheet with a silicone mat or leave unlined. Place the baking sheet in the oven while it preheats.

Add Brussels sprouts, oil, 1/2 tsp salt, and pepper to a large bowl. Toss to coat evenly.

Remove baking sheet from the oven. Add sprouts cut side down to the baking sheet.

Roast for 20 to 25 minutes.

While the sprouts are roasting, add honey to a small saucepan over medium high heat. Once simmering, reduce heat to medium low and cook for another 3 to 4 minutes.

Stir in vinegar and red pepper flakes. Return to medium heat and stir in butter and 1/2 tsp salt. Continue to cook, whisking constantly, until the glaze is glossy and thickened, about 3 to 4 minutes.

Add cooked sprouts to a large bowl and toss with the glaze. Add to serving platter and top with zest.

Serve immediately.