Notes: I used a mixed berry mixture for these muffins, but you could also try frozen blueberries or raspberries. I did enjoy the surprise element of using mixed berries though – each muffin ended up with a slightly different combination of fruits! The cooked muffins can be stored for 2-3 days at room temperature, a week in the fridge or 2-3 months in the freezer – when freezing, be sure to wrap them well to prevent freezer burn.