Arrange a rack in the middle of the oven and heat the oven to 425°F. Place 2 pounds peeled and cut carrot pieces on a rimmed baking sheet.

Melt 3 tablespoons unsalted butter in a small saucepan over medium heat. Add 3 minced garlic cloves and cook, swirling occasionally, until the garlic is fragrant, about 30 seconds. Remove the pan from the heat. Add 1 ½ tablespoons honey and whisk to combine.

Drizzle half the honey glaze over the carrots and toss to coat. Season with 1 teaspoon kosher salt and ¼ teaspoon black pepper, and toss to coat again. Spread the carrots into an even layer.

Roast for 15 minutes. Toss the carrots, then roast until the carrots are tender and the bottoms are browned, 15 to 20 minutes more. Drizzle the remaining honey glaze and squeeze the juice from ½ small lemon over the carrots, and toss to coat. Transfer to a serving bowl. Garnish with chopped fresh parsley leaves, if using.