Yes, you can freeze this peanut butter baked oatmeal. Here's how: Let the oatmeal cool to room temperature. Cut into individual squares. Wrap each square in plastic wrap, then put it in an airtight container and store in the freezer. To reheat: remove a piece of baked oatmeal from the freezer, remove the plastic wrap and warm on a microwave-safe plate for 30-60 seconds.