Once you have made your blondies, you will need to allow them to cool completely to store them. Place in an airtight container or storage bag and store for up to one week on the counter. No need to put these in the fridge.  To freeze blondies, slice them to the size that you want to serve them. Once you have cut your bars, transfer them to a freezer-safe container or freezer bag. Freeze for up to three months. To thaw, simply place on the counter until warm.