In a large mixing bowl, whisk together vanilla yogurt, honey, and water until well combined.
Stir in the rolled oats and ground cinnamon (if using) and mix until fully incorporated.
Cover with plastic wrap or a tight-fitting lid and place in the refrigerator for at least 6 hours or overnight.
In the morning, give it a quick stir.
Divide the overnight yogurt oats into bowls (or jars) and, if preferred, garnish them with your favorite toppings and a drizzle of honey.