Add butter to the Instant Pot. Using the display panel select the SAUTE function.
When butter melts, add the oats and saute, stirring often, for about 5 minutes or until slightly toasted and fragrant.
Add the water and salt and stir to combine, ensuring all oats are submerged.
Turn the pot off by selecting CANCEL, then secure the lid, making sure the vent is closed.
Using the display panel select the MANUAL or PRESSURE COOK function*. Use the +/- keys and program the Instant Pot for 12 minutes.
Meanwhile, in a small bowl, mix together 1/4 cup brown sugar and cinnamon.
In a medium bowl, beat together cream cheese, powdered sugar and milk. Load the cream cheese mixture in a piping bag (or use a plastic bag and snip off the corner).
When the cooking time is up, quick-release the pressure.
Add raisins and 1/4 cup brown sugar. Stir the oatmeal to incorporate remaining liquid and achieve desired consistency
Divide the oatmeal into individual bowls. Sprinkle the brown sugar mixture evenly over each serving and top with a spiral of cream cheese icing. Serve hot, garnished with additional cinnamon (optional)
*The MANUAL and PRESSURE COOK buttons are interchangeable.