Peel and slice the carrots. I tend to like the thicker chunks of carrot, so don't go too crazy, just roughly chopped is fine. Set side.
In a small saucepan add the butter. Turn the heat to medium or just above medium. Stir occasionally until the butter starts to foam and ultimately turns brown. There will be silty brown "bits" that have separated from the yellow liquid. Immediately transfer the mixture to your slow cooker.
Add the salt, sugar, bay leaves, and vanilla and stir. Add the carrots and stir to coat.
Cook on high for about 3 hours or until tender.
Sprinkle with chopped parsley or sage.
The glaze is really great drizzled over mashed potatoes too...just sayin.