Frozen soft pretzels can be reheated in the microwave or in an oven. In the microwave: Place the pretzel on a microwave-safe plate. Place a lightly damp paper towel over the pretzel. Microwave on high for 15 seconds. If needed microwave for another 15 seconds. In the oven: Preheat the oven to 325℉. Mist the pretzel with a small amount of water and then wrap it in aluminum foil. Bake for 5 minutes. If the pretzel isn't warm enough then return it to the oven and bake for a few more minutes.