As mentioned, it's not generally considered safe to use bare polymer clay in stretched earlobes. There are a few things you can do to avoid that direct contact though.
If you're interested in the whole issue, check out this page at my site:http://glassattic.com/polymer/jewelry.htm
(click on the Jewelry category, then scroll down to the section on "for stretched earlobes")
Some people don't care or don't understand about the possibility of getting plastic chemicals in their bodies though (especially the effects after many years), so some seem to have no concerns especially when young.
As for the problems you mentioned about baking shapes that aren't pressed together, that shape couldn't be made around a dowel which is the usual way that spiral logs are made.
You'd need to use a firm clay** in any case and perhaps even cool it well before shaping.
Then you could do something before baking like forming the long tapered logs over 3 short lengths of wood dowel of different sizes (or make your own dowels with rolled-up paper logs), and bake everything on a nest of polyester fiberfill or tissues (which you could also use for the holes), or in a pile of baking soda, etc.
I'd guess you could also hang the earrings with their space holders in place while baking by attaching a wire with a hook shape on each end of the top dowel length. Or if the clay is firm enough, perhaps just baking on fiberfill, etc, would be fine.
Another consideration would be the brand/line of polymer clay. Is the earring intended to be pulled apart when threading one side through the earlobe? In that case you'd need to be sure you used a strong brand/line of polymer clay** and perhaps even mix a regular polymer clay with some Superflex polymer clay (or perhaps MixQuick?) for more flexibility, especially over time (although "thin" polymer clay is always flexible and strong if baked sufficiently).