Lightly oil a baking sheet or coat with nonstick spray. Place carrots in a single layer onto the prepared baking sheet. Add olive oil, salt and pepper, to taste. Gently toss to combine.
Place into oven and bake for 10-12 minutes, or until just tender.*
In a small saucepan over medium heat, combine butter, brown sugar, orange zest, molasses, cinnamon and nutmeg, stirring constantly, until sugar is dissolved and mixture is bubbly, about 4-5 minutes.
Reduce heat; stir in carrots and cook, stirring occasionally, until glazed and heated through, about 3-4 minutes.
Serve immediately, garnished with reserved tops, if desired.
Notes
*Cooking time will vary depending on the size and thickness of the carrots.