Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius). Line a baking sheet with parchment paper.
Place the carrots on the lined baking sheet. Drizzle the carrots with the olive oil, and season with the salt and ground black pepper. Toss to combine.
Roast the carrots for 25 to 40 minutes, depending on the size of carrots, shaking the pan every 10 minutes, or until cooked-through and nicely browned.
While carrots are cooking, begin to prepare the glaze by adding the honey and balsamic vinegar to a small saucepan. Cook over medium heat, stirring often, for about 5 minutes, until thickened.
Remove the glaze from the heat, add the butter, and stir until the butter is melted and well-combined.
When the carrots are roasted, toss with the honey balsamic glaze, and then return to the oven for another 5 to 10 minutes, or until the glaze thickens and coats the carrots.
Transfer the carrots to a serving dish and sprinkle with a few more drops of the balsamic vinegar and some sea salt, if desired.
Garnish with the chopped parsley, if using. Serve hot or warm, as desired.