Store any leftover cookie cake slices in the refrigerator for up to 3 days when placed in an airtight container. You can also make your giant cookie pizza ahead of time and wrap it tightly in plastic wrap in the pizza pan, leaving any cream cheese topping just prior to serving. 2. Baked Giant Cookie Cake can also be stored in the freezer for 3 -4 weeks when stored in an airtight container or wrapped in plastic wrap in the pizza pan. Defrost at room temperature and add it to the oven to heat it if you prefer it served warm.  3. In both instances above, it’s important to first allow the baked giant cookie cake to completely cool prior to any storing as remaining heat will cause condensation which could result in your cookie cake becoming soggy.