Baked egg muffins can be frozen and reheated. Let the cooked muffins cool completely. Then wrap each egg muffin in a piece of wax paper, transfer them to a large Ziploc bag and freeze for up to one month. To reheat in the microwave, wrap in a paper towel and heat on 80% power for about 2 minutes. To reheat in the oven, preheat the oven to 200 degrees. Warm the muffins for 10 minutes or until heated through.