G'afternoon jenny.....Both myself and wife are ok. Hope you are likewise.
I look into AB every day but have become very selective in the threads I become involved and only respond to folk such as you who I consider are nice ABers.
Anyway I am digressing somewhat from your original question and would like to comment further on the subject matter.
The Microwave idea is a good one and so is the pressure cooker suggestion. Also you could put the sponge on a plate and possibly place it on a kitchen work surface with the bowl, in which you made the sponge mixture, upturned on top of the cooked item.
The main thing is that you avoid the Fridge which will have a drying effect on the cake. It may appear strange, but if you wrapped the Sponge and put it in the Freezer it would last for a period of about two months. ; but would need quite a number of hours to defrost.
Hans.