Turn Instant Pot to Saute and add the butter to the insert. Allow the butter to melt in the insert then add all of the spices, brown sugar and molasses; stir to completely combine.
Add the steel-cut oats and water and stir to combine. Lock the lid in place, ensuring the vent is sealed. Select the Porridge setting, High Pressure and 12 minutes.
When the cooking is completely allow 10 minutes of natural release. Follow with a manual relase of the remaining pressue. Remove the lid and stir the oats (there will be a layer of liquid on the top) and allow to sit on the Warm seting for 1-2 minutes before serving. Top with eggnog and any other favorite toppings.
The cooking time is 12 minutes with a 10 minute natural release.
The time for the Instant Pot to come to pressure may vary but 10 minutes would be an estimated time.
This recipe prepared in a 6-quart Instant Pot.