Stovetop oatmeal: Bring the water to a boil in a large saucepan. Stir in the oats, salt, and cinnamon. Reduce the heat to medium. Cook for about 6 to 7 minutes, stirring occasionally, until creamy and the liquid is mostly absorbed. Remove from the heat and let stand for 2 minutes, which allows more liquid to be absorbed (or you can spoon into bowls and then rest).
Microwave oatmeal: Place the ingredients in a microwave-safe bowl with tall sides. Microwave on High for 2 minutes (if there is still a good amount of liquid, cook 10 to 20 more seconds). Stir and allow to stand for 2 minutes to allow the liquid to be absorbed. (For a double recipe, double ingredients and microwave 3.5 minutes).
Top with a drizzle of maple syrup, milk, and additional toppings as desired. Serve immediately or refrigerate for up to 5 days.
