In an electric blender, process the oatmeal and water until oats are pulverized. Pour oatmeal mixture into a 3-quart or larger heavy-bottom pot and place over medium-high heat. Add sugar, milk, cinnamon stick and salt.
Stirring almost constantly, bring oatmeal to a low boil. Reduce heat to prevent oatmeal from boiling over and, stirring constantly, cook for about 5 minutes or until volume is reduced by one-third. Remove from heat and cool to a drinkable temperature. Serve in mugs with ground cinnamon atop each serving if desired.
