I made a no-oil sponge cake for a swiss roll. I filled it with fresh whipped cream and then stored the cake in the fridge. It has gone moldy within 4 days of filling it.  Since filling it, it has been stored in the fridge. Why did it go moldy so quickly? 
When I was young in Asia, my mom would bake a cake on a coal stove in a cast iron pot. Hot coals were then added on top of the lid as a secondary heat source. 