Add the baby carrots to the insert of a 6qt slow cooker.
Sprinkle in the salt, cinnamon, and brown sugar. Stir well to combine.
Pour in the maple syrup and toss well to distribute the maple syrup.
Spread the coated carrots out evenly in the slow cooker.
Top with the cubes of butter, and add the lid to the slow cooker.
Cook on "high" for 3 hours, or on "low" for 5-6 hours. If possible, stir the carrots 1-2 times during the cook time.
To thicken the glaze, remove the lid for the final 30 minutes of cooking and switch to "high." Cook until the glaze has thickened. Alternatively, transfer the carrots to a large bowl and cover with a plate to keep warm. Transfer the liquid to a saucepan and bring to a simmer over medium-high heat. Whisk, cooking until thickened, about 5 minutes. The saucepan works the best for this particular recipe.