Mix first 5 ingredients in large mixing bowl.
Add bread and press down until bread is completely covered by mixture.
Soak for an hour in the refrigerator.
Spray your Instant Pot with cooking spray and pour in the mixture.
Slice butter and place around top of mixture in pot.
Close the lid of your Instant Pot, press the Multigrain function and adjust to 35 minutes.
Open the lid of your Instant Pot and check the inside of the bread. If it's moist, it's done! If it's still too wet, close the Instant Pot and cook again for 5 minutes.
Once the bread pudding is fully cooked, turn off the Instant Pot and let cool.
Place a pot on medium heat on the stove. Add the butter, sugar, and rum extract.