In a large non-stick pan over medium-high heat, melt the butter. Add apples and cinnamon and cook stirring, for about 3 to 5 minutes until they have softened. Once the apples are soft, add in the maple syrup and turn off the heat.
Meanwhile, in a medium saucepan over medium heat, combine the oats, water, and salt. Cook for 4-5 minutes or until thickened and creamy.
Remove the cooked oatmeal from heat, and add in the cooked apple. Stir to combine and top with additional cinnamon and sliced apple.