Generally, Oreo dessert recipes will last at least two weeks at room temperature in an airtight container. So you're able to make these ahead of time, if you're making them for gifts or for a party. If you need them to last longer than that, you can store them in the fridge in an airtight container. Regardless of if you store them in or out of the fridge, you'll want to add a single layer, then top it with parchment paper before adding a second layer. This will prevent them from sticking together, making it a lot easier for you to gift or eat them.