*The bananas can be left frozen until ready to frost, but if you leave them longer than 30 minutes they will be slightly frozen even once you toast them. They are still delicious slightly frozen though! You can also keep the bananas (unfrosted) in the fridge for 4 hours or so, but any longer and they will probably start to brown. **Marshmallow frosting is from [Martha Stewart | http://www.marthastewart.com/314199/marshmallow-frosting]