Heat milk in a large pot. Bring to a simmer and oatmeal. I used “3 minute” Irish oatmeal. Season with cinnamon, then add sugar – white or brown, your preference.
Simmer for about 10 minutes and then give a buzz with an immersion blender. You could also puree it in a regular blender too.
Chill in the fridge. When ready to drink, add extra milk to thin to desired consistency and stir. Serve with some extra cinnamon and a big grin.