Robin: my go to substitution for cookies and bars is half coconut flour and half blanched almond flour. It might work for something dense like this rice cake though it won't have the same mochi-like texture. I would use all coconut milk and skip the dairy. If you're really trying to be good you might try making an almond-flavoured panna cotta using gelatin and coconut milk and leave out the starch altogether.
As for glutinous rice, it does not contain resistant starch. Rather, it is very low in amylose, which is the starch that is resistant to digestion. This means it digests quite readily, which is why some people with AS report being able to tolerate it: rapid digestion early in the small intestine means it is less likely to make it to the starch-loving bacteria that cause our problems.
Suspected SpA. HLA B27, xray, u/sound, blood tests all -ve. Ancient history of plantar fasciitis, SI joint pain, knee arthritis. Recent history of tendinitis, neck pain, debilitating finger pain and stiffness (especially mornings). No diagnosis, no meds.
2010 - stopped eating dairy
2012 - stopped eating wheat
2014 - stopped eating all grains
Jan 2017 - discovered NSD - 98% improvement in symptoms, continually amazed by my results, wish I'd found kickAS sooner