Optional toppings: Sliced apples and toasted pecans
In a 6-qt. electric pressure cooker, combine the first 7 ingredients. Lock lid; close pressure-release valve. Adjust to pressure-cook on high for 5 minutes. Let pressure release naturally. Press cancel.
Stir in chopped apple. Let stand 10 minutes before serving (oatmeal will thicken upon standing). If desired, top servings with sliced apples, pecans and additional syrup.