Place the oats and 1 1/2 cups of milk in a saucepan over medium-low heat. Add the salt and cinnamon. Stir to combine. In the meantime, froth or steam the remaining 1 cup of milk. Add about 3/4 cup of the steamed, frothed milk to the oats. Stir in the grated apple. Cook, stirring often, until the oats are super creamy and milky and the apple is softened. Remove from heat. Stir in the remaining milk. Stir in the brown sugar and vanilla extract.
Spoon the oatmeal into two mugs equally. Top each with a shot or 2 of espresso. Finish off with some extra cinnamon and granola or nuts on top. Sip and spoon!