1. Preheat oven to 425 degrees Fahrenheit (220 degrees Celsius).
2. Place the marshmallows on a lined, sprayed baking sheet. Place in oven and bake for four to five minutes. Remove and let cool.
3. Meanwhile, defrost the ice cream for about half an hour. Place into a mixing bowl and add the marshmallows. Mix well and return to the original container or a pan to freeze. Freeze until serving.