Place carrots in the slow cooker.
In a small bowl, whisk together melted butter, honey, brown sugar, salt, pepper, and cinnamon (if using).
Pour the mixture over the carrots and toss to coat evenly.
Cover and cook on low for 4–5 hours or high for 2–3 hours, until carrots are tender.
Stir before serving, garnish with parsley, and enjoy warm.
Tip: These pair beautifully with roasted meats or as part of a cozy, home-style vegetarian spread.
