Donuts generally freeze well for up to 3 months although I always opt to leave any glazed or sugar coating off if I intend making these ahead of time to store in the freezer. To thaw, simply place them in the refrigerator or on the countertop. You can reheat your donuts by placing a damp paper towel over them and microwaving them for about 30 seconds. It’s at this stage that I’d add the sugar coating.