Add 3.5 cups of water to the pot, stir, and bring the oats to a rolling boil. Let the oats boil for 1 minute, stir, turn off the heat, and immediately cover the pot with the lid. Leave at room temperature overnight.
The next morning, reheat the oatmeal, adding additional 1/2 cup of water, if desired. Alternatively, you can layer the cold oatmeal in a jar with sliced bananas, apple butter, and sunflower seed butter, or any other fruit and/or toppings you desire.