Foundation Walls for Basement with Earth Bags?

We have an existing farm house that we are tearing the floor out of in one of the rooms to build a basement room. Just a place where we can go to be cool in the summer time. There is a crawl space with a 3' concrete foundation, but we would like to dig it 5' deeper and use earth bags as the walls for this room. We aren't digging near the foundation because we don't want to disturb that soil, but we are coming in to create a smaller room and would like to use earth bags and cob. Is this possible in this situation? We live in Kansas and it can get very humid in the summer. Our 100 year old storm shelter that we currently have seems to always be moist in the inside and it is made of concrete. Will we have the same problem with this construction method? We also want to have a cob floor in the basement. Is this possible? We are new to building with this type of material so if anyone could help us out we would appreciate it. We are open for all cheap suggestions. Thanks all!

Use a vapor barrier and at least R-4 insulation between the dirt and concrete slab or other building material.

Basements and foundations poured more than 15 years ago usually lack these, but it is modern code in most places.

What you use to finish the space is up to you, but code demands 6" concrete, reinforced.