Heat the milk and water in a small saucepan. Add in the oats and chia seeds. Bring to a boil, and reduce the heat. Allow to simmer for 4-5 minutes, stirring occasionally. Remove from heat and mix in the Nutella. Set aside.
Meanwhile, in a small bowl, mix together the frosting ingredients until smooth. Set aside.
Pour the oatmeal into a bowl, and top with the frosting.