In a saucepan, bring the water and milk to a gentle boil.
Stir in the oats, shredded carrots, raisins, cinnamon, ginger, nutmeg, brown sugar, vanilla, and salt and return to a boil.
Decrease the heat to low and partially cover. Cook the oats until they begin to thicken and become soft-yet-chewy, stirring once or twice (25 to 30 minutes).
Remove from the heat and stir in the orange zest. Cover and let sit for 5 minutes before serving.
Serve warm with an extra glug of warmed milk, if you’d like. This is a great make-ahead healthy breakfast as well, as it reheats nicely!