On a cutting board, cut the apple into quarters and cut out the seeds. Cut the quarters into slices and then dice the apple into small to medium-sized dice. You do not need to peel the apple.
In a medium-sized saucepan, add the water, milk, oatmeal, brown sugar, salt, diced apple, and spices. Stir well.
Over medium heat bring the oatmeal mixture to a slow boil. If you boil this at a high heat it can bubble up and burn the oatmeal.
Add the cranberries and stir. If you are using frozen cranberries they do not need to thaw.
Lower the heat and let simmer for about 10 minutes, stirring occasionally until the oatmeal is thick and creamy and the apples are cooked. You should hear the cranberries popping as they get hot.
If the oatmeal gets too thick add a little water to the pot until it is the consistency you like. I usually add water a tablespoon at a time.
When done, pour the oatmeal into bowls and top with a splash of milk,a sprinkle of brown sugar, and more cinnamon if you like